One thing to do, take your plane up high, and do a series of slow flight passes and straight ahead stalls. Work on seeing just how slow you can fly and maintain altitude, and how slow you can fly and manage a moderate decent. If the airspeed you get this way is noticeably lower than your landing speeds, then you can slow the plane down more. If not, then check the CG and maybe move it back a bit and try slow flight again. Oh, don't fly your approach quite as slowly as you do in the above exercise. You want to leave a little reserve for wind gusts, turns etc.

I had a student who was having trouble slowing his plane down do this, and it really made a huge improvement on his landings immediately. He just didn't beleive me when I said "slower, you can fly it slower" until he took it up high and saw just how slow it would fly. It also reduces the "fear of stall" a bit.