Fully agree with what most folk have already said - ie don't over edit the photos or add black borders. Your crops are also too tight and the composition lets them down. When I first started photographing models I looked and saved all the images online that I loved , whether it would be the models pose, quirky idea, editing technique etc... I would then look through these a few hours before a shoot and I would incorporate these into the shoot. You'll then start to realise what works and what doesn't. Shoot at lots of different angles - shoot low, shoot high, shoot at eye level.