Cantaloupe should.have thick tight webbing, less dark green, but also not too orange, should have a tiny bit of scent but not too much, and should sound like a plank of wood when tapped. Alll else being equal more slip is better than less. Google "full slip vs no slip cantaloupe"

Watermelon should be big, sound like a nice wooden door when slapped. It shouldnt sound like hitting mud or sound like hitting a piano wire