If you go to Hobby Lobby or a similar craft / hobbyist store, here are some items that you may find useful for microscopy:
1) optically clear glue that works better than clear nail polish:
https://www.hobbylobby.com/Crafts-Hobbi ... nd/p/28110
See last few posts of this thread for discussion, if you need it: viewtopic.php?f=10&t=3559
2) black and optically inert cardstock for background and flocking:
https://www.hobbylobby.com/Scrapbook-Pa ... 2/p/100914
Discussion here: http://www.photomacrography.net/forum/v ... sc&start=0
3) dry specimen organizers: https://www.hobbylobby.com/Beads-Jewelr ... es/p/11367
https://www.hobbylobby.com/Beads-Jewelr ... er/p/99061
The (first) small organizer can fit into individual spaces of the (second) big organizer.
4) from their jewelry making / bead isle, you can find small plank metal pieces of defined thickness (around 0.5-1.2mm, if I remember correctly) and metal / plastic threads of defined thickness (0.25-1.2mm).
Those metal planks can be used to make DIY flat well slides or micro aquarium. Threads can be used to parfocalize objectives.
5) this coin holder can be used as low power watch glass:
https://www.hobbylobby.com/Clearance/40 ... p/80794722
6) tiny glass vials with screw or cork top: https://www.hobbylobby.com/Beads-Jewelr ... p/80809949
Quality is only decent though.