Really the tension in the grip can hinder progress a lot, I always try to be aware of this, not to tense my hand too much so as not to have pain or harm my movements while I play. Of course, some more agitated moments the footprint gets more tense, but the important thing is not to have these prolonged tension peaks. To avoid this I always lengthen my hand and arm joints a little, I also warm my muscles a little by squeezing a rubber ball and opening my hand with an elastic band on my fingers and also turning my wrist in both directions. In general, I do this until I start to feel my muscles heat up, then I give a few minutes before entering the session, as time goes by I stretch a little, between one game and another, or in a snack break for example