Remember that you have enlisted their services. In other words, they are working for you. Their work is an investment in which you have put money, and you deserve good returns. They should give you a free title page, formatting, outline, and bibliography.
You probably would like to read the writing before paying for it, wouldn’t you? And if you are unsatisfied with the work, you have a right to ask to edit it. Clients are the priority in such services, so you should be also offered a front page, outline, reference list and structuring at no charge.
The regular chatting with a writer is very important as you are able to control the writing process in this way. Ideally, such a service should have a real-time chat for customers and writers. So, make sure of it in advance.
The students are usually asked to write on a certain topic, right? Some websites specialize merely in writing academic works or articles and might be not suitable for you. Ideally, choose the service that provides the widest range of assignments and topics because you are likely to be asked to do writing tasks throughout the semester.
This includes the general mistakes that you make especially if English is my second language. Your writer also needs to be aware of the books and materials you have used in your class. He can use them as referrals when handling your assignment.