They still had clones, just not as many. And these are the reasons I believe so: 1.) Kamino might be hard to trust after the rebellion. Other planets may produce unstable clones of lesser quality. 2.) Too expensive; much cheaper to just recruit young men and is also faster (don't have to wait for the clones to mature). The clones were useful while they were available, but after a certain point, they were unneeded.

Also I believe somewhere in the Heirs to the Empire books, Mora says something like the emperor didn't like the idea of an army of one man. It's been awhile since I read it though.