Playing on grass just after it rained was always fun, we would give it a quick mow with the blades set down low and we would have a nice juicy greentop.
Surprisingly batting was sometimes easier against pace on a wet pitch, because the ball tended to skid through nice and straight and give the batsman more chance to straight drive the ball, whereas on a dry pitch the bounce was unpredictable and the ball tended to hold up at times and make timing difficult.
This was with a tennis ball, sometimes taped up on one side but more often than not without tape because it usually fell off or became tattered after a few overs.
Making the pitch slightly shorter than in proper competitive cricket works well with a tennis ball, because a tennis ball loses too much pace before it gets to the other end on a full length pitch, 20 paces is about right.
As for tactics, spin was best when a batsman was being defensive, while pace was best when a batsman was having a slog.