I've been shooting modeling portfolio shots for over twenty years so i am starting to get fairly good at it ! The most important thing, apart from obviously taking a nice shot, is to get some personality into expression or pose. Especially now the the use of the internet, model pictures will be seen by many viewers and compared with hundreds of others. Its vital to have pictures that are a little bit different and not just copy others, or repeat popular poses. This isn't as difficult as it may sound, its just that many photographers, even good ones, aren't always good at directing models to get the best out of them, especially if they are concentratiing on lighting and the look of the whole photo. I see a lot of good shots wasted because the model just looks bored or uncomfortable. Thats why I do make an effort to make them look interested abd involved in what they are doing. I like them to smile, or at least look awake ! And I try never to take the same shot twice. That's also important in the internet world. Most of the time I only use a small studio set-up but I change lighting and backgounds and lots of little things to make it look different. I also shoot mostly in camera - although I work in Photoshop every day and have seveb years digital experience - my photos have very little "digital enhancement". A pretty girl with good skin shouldn't need it if the photographer has done his job right.