Food and Water Dishes
For food dishes you will want something shallow, sturdy, and easy to clean. Flattened heavy plastic dishes made to look like rocks can be found in the reptile section, or you can use shallow ceramic dishes made for small animals. Some people also use natural sea shells (the flatter half shells) for feeding.
Since all species of hermit crabs should have access to both fresh and salt water you will need two water dishes. They should be big and deep enough to let the crabs get into them if they wish to soak (especially the slat water dish), but easy to get out of and not so deep that drowning is a risk (strawberry hermit crabs should be given a salt pool deep enough to fully submerge themselves in, but for most species it does not need to be that deep). With deeper dishes, smooth river stones or pieces of coral can be used as ramps or steps for the crabs to get out of the water. ZooMed makes a nice water bowl (Hermit Crab Ramp Bowl) that is attractive and is good for hermit crabs due to the stepped edges for easy access in and out, and their Repti Rock dishes work well too. You should also place natural sea sponges in the water dishes; some crabs will press on these to get water to drink and they help regulate the humidity.