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.
Some of those sites employ non-native speakers and writers without university degrees and that might impact on the quality of their works. To avoid this, read as much custom reviews as possible. You can also check the requirements for applying on the service as a freelance writer.
In college, a student gets to write too many types of essays. The type of essay writing service you hire must be able to write in good time. If you need an argumentative essay and all they can manage is an expository essay, then they are not the best source of help.
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.
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.