I'm in Diamond and I was wondering, is it better to have a Pokemon with static leading the party to make electric types show up more often or should I have a Pokemon with compoundeyes to increase the chance of it holding an item
The best idea is Compoundeyes. Pikachu very rarely holds a light ball, and Compoundeyes really helps. Remember that in Trophy Gardens there is also Pichu, which is drawn in by Static. Pichu doesnt hold a light ball. Though it may be a bit harder to find Pikachu without Static, the chance of finding a light-ball holding pikachu is much greater. Also try the PokeRadar. I was actually using it in Trophy Gardens to find a light ball when I found a shiney Pikachu! Besides finding shiny Pokemon, its purpose is to encounter the same Pokemon over and over. This works amazingly with Compoundeyes. I hope this helps you and you find a light ball! -Jellohamster
Yes, compoundeyes increases the chance of a wild Pokemon holding an item by 50 % in gen 4, but a better idea is to use theif or trick to get Red's pikachu's light ball in HG SS.
Source: Bulbapedia