Your problem is not about avoiding range bound days as such. Your problem is that you only have 1 method for a market, large range days or breakout trades (Yep I'm assuming) and are unable to firstly develops others, like techs first post, and then turn the right method on at the right time to match the market (the daytraders holy grail).
This is the problem with day trading probably more so than longer term trading. A multi year bull market is much easier to recognise than the daily even hourly changes of an intraday market.