As I look around forums and trading systems, I see people using one indicator (even some using none) and people using 5, 6, 7 or more.
I’m not asking for indicator recommendations, here, but which is a better approach, in principle? Many indicators, or few?
Few are better than many. 
Simple rule: use an indicator only when the answer to both these questions is Yes
Does it display information which you can’t use your strategy without having displayed?
Is using it the only (or by far the easiest) way to get that information in front of you?
The strategy aim and definition should come before the indicator.
Avoid the big mistake of trying to build the strategy from the indicators. That isn’t a recipe for success! 
And welcome to the forum. 
I prefer few. Otherwise I’m dealing with second-hand information about price, rather than dealing with price.
The great analogy in this post by @tommor helped me to understand it, and I think it will probably help you, too
Apart from non-indicator, price action stuff like support and resistance, the three things that matter most to me, about what trading charts show, are volatility, trend and momentum. And maybe momentum’s the most important of those three? If you trade on fastish charts, anyway.
It might help you to use an absolute maximum of one indicator for each of those three things, if you think you really need indicator for each, and if you‘re using a strategy that depends on knowing about all those parameters. Such as ATR as a volatility indicator. Just as one example. I’m deliberately not making suggestions for the other two because you said you’re not really asking for recommendations, and hundreds of other threads cover those.
Use indicators to help you to display those three things only if you’re sure you need each one of the three, and only when you’re certain which indicators display which, and how!
(The other thing - the possible fourth important parameter - in trading, generally, is volume. But you obviously can’t know that with spot forex, since spot forex is decentralized so it can’t be measured or recorded.)
Fewer indicators are better, overall, than more.
Multiple indicators used as attempted filters are a way to trade less often, not in practice a way to prevent losses while preserving profits.
Don’t imagine that trying to confirm trade entries with multiple indicators will help, overall. As a general policy, it usually won’t.
If price movements after you’ve entered a trade disappoint your expectations from a couple of indicators, they’ll normally disappoint your expectations from more indicators, too. That’s always because something happened after you entered the trade that changed the balance between buying pressure and selling pressure (there’s no other way for prices to move!), and when that’s so, then at its simplest level there’s no reason why your third and fourth indicators should help any more than your first and second.
Simple indicators will also usually help more than complex ones.
The important thing to stay very aware of is that almost all of the indicators that retail forex traders use were originally designed for use on daily charts, and for stocks, and that most of their standard/original settings were invented and intended for that use (and some of them - like MACD and Ichimoku - had their settings calculated specifically for a 6-day week, too, so if anyone tells you to “just use the original settings”, you ight want to take them off your Christmas-card list!).
Try to take advice from profitable traders, not from marketers (people who want your email address and/or have Youtube channels). This suggestion’s really difficult, because it rests on your ability correctly to identify profitable traders, and that’s hard, especially when you’re new.
A longer-term tip is that very few steadily profitable traders are trading mostly spot forex CFDs. There are several reasons for this, but it really takes a lot of experience to understand them. Sorry if that sounds pretty unhelpful, but it is what it is, unfortunately, and “true” is part of what it is!
Welcome to Babypips! 
I don’t use indicators, well not in the traditional sense. I also don’t trade forex, but the only indicator I use draws a line at a market’s close and a box around the overnight range. I use them to determine whether a market is likely to breakout or range. Either way can be profitable unless it’s a tight range and then it’s just boring.
But my waffley point is to say, indicators don’t work as entry and exit signals. They don’t tell you anything that the chart doesn’t and understanding what they’re telling you, in a world of bad information is very difficult.
Using indicators to filter entry/exit points only make a fixed set of available trades in which to quantify trade statistics. If trading is a career, you’re going to take a lot of trades. If using indication based on historical prices, you’re hoping for a system that follows it’s expected value closed… without volatility.
Ie; Strategy A that wins 20-49% of the time at a R-multiple of 2. vs Strategy B that wins 30%-36% of the time at 2R. When the expected win rate would be 33%.
It won’t be the expected value that loses an account, it’ll be the imbalance of the distribution for wins & losses.
I’ve noticed this when buying a sell signal & selling a buy signal that yielded the same results.
I personally don’t use any indicators.
I don’t really believe in indicators as all my testing around them shows win rates of around 50% so over a long period of time none are really profitable for me.
I do like to have SMAs on my charts, 50, 100 and 200 as I do notice price often reacts to them as support and resistance levels, that can be useful information.
I started with Support and Resistance (SnR) levels, as I once read that if you know how to place them correctly in both trending and consolidating markets, there’s nothing more effective than this.
To start with I’d say learning S&R, chart patterns and candlestick patterns are probably the most important.
Then add indicators if you wish, add them slowly and see if they prove valuable.
You generally don’t want to use too many indicators as they start contradicting each other pretty fast!
I have often found that different indicators work with different strategies and different instruments.
I use Pivot Points when trading the Bund but not when trading FX for example.
For me, the big question was always “does it show what I need to see, to operate my strategy?” As a couple of people said up above, more or less.
In other words, I wouldn’t have wanted to add any indicator unless I needed it, to answer a specific need of my system.
Otherwise I wouldn’t ever have known which one to add, let alone what an appropriate setting would be for my purpose.
Now, with more experience, I know that “adding indicators to see if they help” is a misguided approach (for me, at least), and one that leads to trying to build a system from the indicators rather than the other way around.
All trading forums are full of threads and posts saying “indicators don’t work” and “indicators don’t help me” and I always think, when I read all that stuff, that those must be people who tried “adding indicators slowly and seeing if they proved valuable”.
That boils down to random guessing, IMHO.
They won’t help, of course, will they, if you go about it that way round?
Because you’re not starting by identifying what you actually need, and why.
I use two moving averages to identify “trend” in my timeframe, for my purposes. I don’t care whether, when or how they cross over. I need them either both to be rising (to look at the price action hoping to find a long entry) or both to be falling (to look at the price action hoping to find a short entry). I even show them both in the same color because I don’t care which is which. I find that helpful for the type of intraday trades I want to do.
Fewer is usually better. The more indicators you add, the easier it is to get conflicting signals.
I’m quite surprised to see near-unanimity in the answers (“none or very few”).
I was expecting that a lot of people here would be using multi-indicator methods, as in a couple of other trading forums.
I’m wondering whether those people are maybe just a little reluctant to post, now, after some replies saying “none or very few”?
I use one (a moving average, for directional bias).
For the longest time I used two (moving averages for directional bias) and it took me nearly for ever to realise that I only needed one of them, and lost nothing - probably gained - by removing the slower one. You get used to stuff, I guess, and stick with it?
I use a 20 EMA.
Thats all!
I find the general direction on the 30min bar chart and then fine tune my entries on the 5min bar chart.
Less is definitely more! For me, two indicators are enough.
That’s true of indicators and - in practice - of leverage, also?
If you use Ichimoku, does that count as 1 indicator or 5?! 
4, in my case (I’ve never found the “lagging line” helpful, but I’ll take the rest!).
I’ve seen a few Youtubers who use several indicators to get entry signals, I think there may be something in it but I’m busy trying other systems so I can’t comment if it really does work or not.
They tend to use RSI, MACD, Bollinger bands, SMA or EMA mostly.
I need my Lambo now! 
Take care with the speedbumps.
You may be better off with a Ferrari F8 Spyder, and it has indicators, too, so it’s completely relevant to this thread. They are accessed via a stalk on the steering column, but are probably of only limited value for forex trading.
I use two indicators. One is a Donchian midline crossover (the same thing as an Ichimoku crossover of the Tenkan Sen and Kijun Sen but under a less Japanese name, which is obviously a plus), and the other one isn’t.
Might this in principle be something to prompt us to avoid using them, if we can?
Well that’s easy for you to say, or maybe not san.
I will have a look at that, always interested to learn something new, thanks!