green and yellow squash are staples for my guy because he loves them so much. I usually offer collards as well since they are easy to get and they last for a long time in the fridge. I like to mix in bok choy and mustard greens when they look fresh too. Today there is some celery greens because I just chopped up a bunch of celery for soups. I rotate in bell pepper and chopped green beans quite a bit. Occasionally I'll add a blueberry or some strawberry tops. It's really a matter of combining their individual preferences (which you figure out over time) with what is fresh and available at the store at any given time.