I don't know that I agree with Malcolm.
Good subgrade prep and compaction - yes. Nothing wrong with the right kind of dirt, select fill preferred. No sod, no loam,
Mesh does not reinforce concrete. Rebar in a 4" slab does not help, actually hurts.
Avoid re-entrant corners. Concrete wants to be square, not rectangular. Never exceed 12' in any direction without at least a contraction joint, closer preferred. Cut all contraction joints a minimum of T/4, that is, 1/4 or more of the slab thickness. Most lumberyard jointers cut 1/4" deep. Make sure the keel is at least 1" or you're wasting your time, I prefer 1 1/2. If the contraction joints are sawed into the slab (my preference) they must be sawed the same day as the pour as soon as the concrete doesn't ravel under the blade. You CANNOT wait and cut them the next day. Curing the concrete is crucial. If you use a curing compound, make sure it is compatible with potential floor finishes/adhesives. A 3 day minimum full wet cure is the best.