I'm hoping this will not be the last Talking to Strangers. Some people seem to find this easy, others not... Obviously, I fit well and truly in the latter.
Now, I tend to take people as they are. I don't tend to notice if they are looking particularly gorgeous, although I might if they look exceptionally trashy. If someone asks if I notice anything different, I usually have to guess (haircut/pierced ears etc) until I get it right. But I do feel great when someone sees me and says, "Nice dress". So I've started looking for potential compliments *before* it's a return compliment. Then, at summer school in the first week, a lady was wearing a dress in one of my favourite blue shades and I said, without thinking, "Love your dress".
Of course, once started, this is an easy one to continue, and I've since found several options for initial compliments.