OK, 1st back test a lot, at least 1 or 2 market cycles to make sure your winning strategy is not correlated to the bull market only for example... What to avoi

OK, 1st back test a lot, at least 1 or 2 market cycles to make sure your winning strategy is not correlated to the bull market only for example... What to avoid: avoid everyone who is selling trading strategy (in a books or online gurus and signal sellers), no sane person will do it, because the more people(money) are trading a strategy, the less effective it will become overtime...