Bollinger Band always works, and Weekly MA is not that bad neither. I feel like I do not need a third one, if you really check what’s going on, these two will be hit one way or another if there is a good buying signal, but that doesn't mean that it will work for you, sometimes it looks like it’s going one way and then goes another way so you should always be careful about what’s going on.
You said BB always works, you also said it may not work sometimes because you will think it is going one direction but go opposite direction. Which means it does not always work. No trading indicator that is existing that is always working, a trader has to back up the trading with other strategies to help if a trading indicator fails. I have noticed that out of 10 times I have used BB, it can fail at least, 2 times and if I do not have proper risk management, it can take almost all my profits aways at once.
These indicators are great for when you want to invest, but sometimes you end up failing on them as well if you are not careful and that’s an important thing. I personally feel like BB has been king for me for many years now, but even that fails time to time.
Almost all indicators I have used are good for investing, but investing just depend on the time range of the candle stick chart. The 15 minutes for scalpers, 1 hour and 4 hours for day traders, 1 day candles for swing traders while anyone that wants to invest can use 1 week and month chart. This can be sed with BB, EMA, RSI and many other indicators.
How about RSI?
I use it with BB and they are very good indicators if used together. It is good to combine two indicators together. One of the main ones like MA, EMA, BB can be combined with RSI or other oscillating ones.