I’m not a programmer by trade, but have put a lot of time into learning to code over the last 12 months. I am certainly no expert, but have made a lot of progress in that time.
In terms of development, I don’t use MT4’s strategy tester, but I do use a walk-forward optimization approach that aims to get the most robust parameter settings.
I’ve developed several strategies, and only one of them incorporates any form of price action. This one has the worst backtest performance and is so far performing worst in live trading. Some of my other strategies are based on transformation of the price series (that is, indicators), but not the MACD/Stochastic/RSI type of indicators that are most common. I like indicators derived from digital signal processing, and am a fan of John Ehlers’ work. As well as those, I have two strategies that are based purely on statistical properties of the market being traded. These are relatively new additions to the stable and don’t have much live trading history, but they are the most promising as their development process and backtest results were very robust. If I were starting over again, I would start with the statistical approach.