I have always meant to spend more time training with my shotguns. Unfortunately, neither of my usual ranges allows anything other than slugs to be fired. I've made a few range trips with my shotguns, but it can get expensive running only slugs.
One range we have has a dedicated shotgun range that's open mainly for shooting clays (bring your own machine) but I set up drills by putting clays scattered about on the ground then practice switching between them.