I'm pretty anal about taking care of my equipment. All the same, I don't have any special tools like groove cutters and such. I use an old toothbrush with dish washing liquid to clean the grooves and whatever dirt might be in the number on the bottom.
What I'm particularly careful about it to dry them very well. I don't want water staying in the cavities. When I wipe each club dry, I seem to have developed a habit of wiping the shaft with the towels too.
Since I use graphite shafts, I also look around the hosel area of each club to see if there's any damage from bag clatter.
Besides my clubs, I tend to check my bag every week to make sure I have enough balls, plus tees and some coins in a ziplock bag.
And I can make one god awful mess around the living room if I've been rained on, taking everything out to dry.