In my experience, generally speaking, the simpler the system, the more robust it is. Beginning traders make the mistake of trying to develop a system that is rarely wrong. There is no Holy Grail of systems.
The Holy Grail of trading is inside of you, in terms of knowing yourself and your emotional weakness, and working to trade in a way to minimize harm from your weaknesses
Agree with every word said
From my experience, the best strategy long term wise is simply following the trend, i.e. when the price goes up, you buy in, when it starts to slide down you sell out (using stop-losses or otherwise). If you look at historical data, you will see that this strategy would always bring you profits in the long run, even if it could sometimes bring you small losses when you would have to get out from a losing position. And as you get the hang of it, you can proceed to tweak it so as to squeeze more profits from every price movement but not until then