A good staple diet is important for gliders to make sure they have all the nutrients and vitamins needed, and not too much/too little. There isn't a 'best' diet out of these, just choose what works best for you and your gliders.
There are plenty of great vendors to order from and a lot you can make at home or get at thrift stores also.
Toy Basket/Ball Pit: Basket from the dollar store with ping pong balls, plastic toys, fleece pom poms, etc. Make sure the holes in the basket aren't small enough they can't get their head through so they can't get stuck.
Elephant toy/Baby toys: A lot of people have the Elefun Ball Popper toy. The holes are big enough so they won't get stuck and they can run through it and sleep in it. I've seen similar giraffe toys also that are great. Make sure to remove any batteries. When in doubt, you can make a post to see if it's safe.
Straws/Feathers: These are both favorites of mine. I like to weave them through the cage bars, put them in toys or toy baskets, etc. You can twirl the straws with a whacky whirly(works best) or pencil sharpener for more variety and fun. I sometimes give mine wiffle balls filled with twirled straws or fleece strips, and they absolutely loved pulling them all out and then repeating it. Make sure any feathers are natural and sanitized.
Natural Stuff: Eucalyptus chew sticks, branches, and leaves are all great for gliders, especially if you want to have some natural stuff in their cage. Other types of wood are safe as well, along with some flowers. Just be sure to do your research to be sure what's safe, and that no pesticides or other unsafe chemicals were used them.
http://eucproducts.com/ has everything eucalyptus. They can also include free seeds in your order, and even have subscription boxes!
Cage Sets & Pouches:
You can either buy cage pieces or make them yourself. It's best to buy from an vendor who sews safely with hidden seams. A lot of items from pet stores or amazon may look nice, but have exposed seams, loose stitching, or unsafe fabric. Making your own items isn't too hard; both machine sewn and no-sew items. Hand sewing though, isn't recommended.
You can check out my sewing tutorials here
(LANK) has lots of no-sew tutorials, as well as a lot of other great info.
Cage Size Info:
I also have a list of good cages, just let me know if you want me to post it also.
A lot of people use just soap/water or vinegar/water, but there are better alternatives. I'll link a couple great ones. Chlorhexidine is what vets use to clean kennels and such, it'll need to be diluted 2 tablespoons to a gallon. The peroxide spray is often used in hospitals. These are both awesome at cleaning and getting rid of the smell. I spray the cage down with one(whichever I happen to have), let it sit for 10 minutes, then scrub and wipe clean with a wet rag(or rinse with the water hose).