Are you using any sort of gutload right now?
I use a wide variety of fruits and veggies, and I either put them in my mini food processer and make a "salsa" for them or put slices of the whole fruit or veggie in.
What I use: switching off, I use collard grees, romaine, banana peels, oranges, apple slices and apple skin, kale, sweet potato, carrots and probably other stuff I'm not thinking of!