Practice. You should be able to get sub 20 or very close using that. Try to practice look ahead, by doing slow solves, and then looking for the pieces you're going to use, while solving the other pieces.
So check the cube out, and plan out your first couple of steps. When you start solving slowly, don't watch the pieces you're solving, but look for where the pieces are on the cube that you're going to need next. Then when you start solving those, look for the next pieces, ad consummationem.