I buy frozen green beans, mixed vegetables, cut okra, broccoli florets, sugar snap peas and chopped spinach.
I buy frozen mango, blueberries, blackberries, and cherries.
Melons can be cut up and frozen for longer use. I cut up watermelon, honeydew, cantaloupe and papaya in glider size pieces. Spread the pieces out on a wax paper cookie sheet and put the fruit in the freezer. Once frozen solid, pop the pieces off of the wax paper and transfer them to a zip lock bag. This pre-freezing keeps the pieces separate in the bag for easy serving each night. I keep these on hand in the freezer but I only need to cut up and freeze ONE of them every few weeks.
When I travel, I put the GliderKids staple cube and a night's serving of fruits and vegetables on a plastic baby plate (I use doller store divided baby plates) and then slip the plate into a large zip lock bag and put the whole plate in the freezer.
My son feeds the gliders when I am away - he only needs to take out the zip lock bag and put the plate in the cage. (I have 3 colonies so each of MY bags has 3 plates for the night.) This way my gliders still get a different combination of foods each night I am away.
If you do not have multiple plates, you can just put the nightly feeding in a zip lock bag so your glider sitter just needs to dump its contents on a plate and serve.