Hey Bradley,
First complete your profile. and make it look professional. Write clearly what kind of service you can provide. While bidding, clearly state what you can do, in how much time and any other requirements you have. Once you get a job, make good relations with your counterpart. He/she is the one who will write review for your service, make him feel good. If you will have good relations, they might contact directly to you for future projects. Dont hesitate to ask them to write a review if they havent given you a review, do this politely.
Dont get into something in which you are not comfortable, or the guy seems fishy. Talk to them before starting to work on their project.
Hope this helps.
Zander