If you dont' count sewing buttons, I had zero experience when I attempted my jacket conversion. If you follow the steps in the sticky on jacket conversion by F-H.C.A.G. you'll be all set. The pictures and the play-by-play are brilliant and will walk you right through it. I read through the tutorial several times to make sure I had a general idea in my head of what to do, then just propped the laptop up next to where I was working so I could reference the pictures and make sure what I was doing matched (for the most part) what I was supposed to be doing. I did mine by hand since I didn't have access to a sewing machine and it took a few evenings to complete. With a sewing machine it would probably go even more quickly.

Good luck!