Take care of yourself
If you really want to be a model you need to start taking care of your looks. As the way you look will depend whether you get the job or not. It's important to have healthy skin, nails and hair. Remember before photo shoots to have a good sleep so your eyes won't look tired. You should drink a lot of water and eat healthy. You need to be aware of the fact that your face, hair and the whole body is what matters in the industry. So you really have to take care of yourself.
The healthier you look, the prettier you really are.
It really is as simple as that! It would also be better if you avoided having hair extensions, fake tan, fake eye-lashes, fake nails (and if you decide to have them, choose the ones that look natural not freaky!). You should look good and natural. By showing your natural beauty the potentional agents and employers can tell how they can work with your body and your looks, they don't need to see a ready image but an image they can create with your help and for the campaign needs.
Show your potential
When it comes to your portfolio you should have both: the natural looks images and some original and glamour ones to show your possibilities. So don't be afraid to pose in original, unusual clothes and hairstyles. It shows your flexibility and potential.