Getting Better

I'm not sure if this makes me sound like a beginner or not, but lately I've been practicing the same songs so much that I've started to kind of jam out with them a bit.  Nothing really too exciting since I've mostly been writing fairly formal rock type songs.  What I am doing is trying to make slight changes to the structure each time I play a song.  So far this has helped me remember what I've written the whole way through, try to get some the the specifics right, and I usually end up with cool versions that can be extended if I were at a show and wanted to for some reason.  This almost seems like a normal part of songwriting since it's helping the different parts fit together, but I don't really know for sure.