Slip stitching in the round

[fatoldladyinpjs]

I'm fairly new to crochet. I'm trying to do hats in the round. When I get to the end of the round and slip stitch, I get this horrible hole. How do I do this to transition rounds and still look smooth? Is there any tutorials or videos that you could recommend? I looked at Mikey Sellick's (The Crochet Crowd) Curtzy crochet tutorials on Youtube. He makes it look easy but my transitions look big enough to drive a truck through. Any help you can give me would be appreciated.