I think "Which is easier?" depends on the amount and type of experience you have beforehand; I was primarily a rifle shooter before I tried the clay games, and I found trap really easy (23/25 the very first time I tried it). When it came to skeet, though, I would've been better off just throwing boxes of shells in the fire for the first 2 years I tried it, simply because I didn't have any flying game shotgun experience, and I didn't have any idea of the proper lead to use at each station. Skeet is really about consistency, over and over again, and once you track a clay, squeeze the trigger, follow through, and it turns into a black cloud of dust, something in your brain just "gets it".