I spend about 80% of my time on the water fishing caddis imitations. I like to fish my fly mostly dry/damp. The best bit of advice I can pass along, fish your fly with an active presentation. Swing it, skip it, skate it, twitch it. You very rarely see a caddis fly doing a dead drift, they are very active on the water.
Don't worry to much about a specific pattern, but do vary your presentation if you aren't catching fish, sometimes even if you are. Since caddis are very active, the fish do not have the luxury of being able to closely study the fly, if they wait a second, it's gone.