This is a Real Head-scratcher

I have been looking at all the pictures here and have realized I am doing something wrong. I'm not sure what, though. My poor two repeats do not look the same as anyone else's. Maybe I'm slipping my stitches wrong. I am going to slowly and carefully start another scarf using some stash crap yarn and see where I've gone wrong or if I need to change yarns completely. My scarfette is very, very loose. (Swatches?? I don't need no stinking swatches.) Ya' know, what really bugs me is I'm so not a new knitter. I've never done lace work before but I have made some really complex projects-honest. I am going to do this. (Talk me out of it.)