Depends on the fruit. I pit cherries, I quarter plums, I just crush berries, I roughly chop raisins in the food processor. I always do a freeze/thaw, freeze/thaw with fruit, meaning I freeze & thaw it twice. It really helps to break down cell walls & soften up the fruit. I mash it roughly with a potato masher & contain it in a mesh sack during primary. I just add it to the carbouy in secondary.
Regards, GF.