Even when trying to implement new strategies, it's way better to actually continue with that which you know and has been working for you while you make gradual and slight implementation of that which you intend trying out at the moment and then later you could gradually implement the new strategy and then get going wit it if it's working well enough.
That's correct; trying out new strategies does not mean that the person should abandon the old strategy that he has been making use of, but rather they are just to try out new options that are out there, and even when they have known how that works, they could either combine the two together or be interchanging them based on the occasion that requires each of those strategies and the type of game they want to play at that point.
Any new strategies should be tested in parallel but with a minimum bet. If the old strategy works well for you, or maybe with some interruptions, then you should not immediately try to implement something new into it, leave it until you find something better, and test everything new separately, but with minimum bets that could not affect your bankroll in any way. Check it several times and only then (if it works well), start implementing it into the current one.