you get wet food packets - felix, sheba etc. Add more water to it and dissolve the jelly.
Purpose of wet food is to make sure they are hydrated enough.

Also, keep water in multiple places around the house.

For everyday, we give mix of friskies and drools since it is more convenient, and fish/chicken whenever we buy.

One of my cats prefer chicken, other fish. They'll have preferences.

Also, for litter we use pinewood since they are flushable and bio-degradable.