Cheap way to do non-skid as follows:
Tape off area that you want to have non-skid. Paint inside of the taped area with paint of choice. While that paint is still wet, sprinkle with sand. The next day after the paint has dryed, vaccum off the excess sand, and remove all the tape. Now, paint the entire deck area, including the areas with sand, using your paint of choice. A roller works best, as a brush tends to push the sand around a little bit. You can then tip off the areas without sand using a brush. You can change the aggressiveness of the final non-skid by using courser or finer sand. I learned this method in the military. Back then we used blasting sand for a very aggressive non-skid deck. Recently I did this on the deck of a small skiff I own. I used playsand for the non-skid material, and painted with an Alkyd enamel oil based paint. The playsand is not real aggressive. It is comfortable when in bare feet, but still has good non-skid properties.
YMMV
eric