Usually have a couple of sleeves of new balls and several loose balls in the bag.
I generally start the round with a new ball and sometimes will change to a used ball on tough holes.
My go to ball is the Srixon Soft Feels. Right now in addition I have some TaylorMade Project A's, Vice Pro Softs, Callaway Chrome Soft and SuperSofts in the loose ball mix.
Not a ball hawker unless itโs my ball. Iโll use a ball until I lose it typically.