A large writing project such as a thesis or dissertation requires a lot of work and planning, mastery in a variety of skills, as well as the heavy involvement of an advisor, and often, a committee of advisors. Sometimes, students feel overwhelmed with all this work and feel they need some help they are not getting (and probably should not get) from their advisors.
Advisors are there to help plan the project, make sure the project qualifies as a final project, and guide the student's decisions along the way. However, as the student continues with his/her project, s/he may find him/herself weak in certain skills, such as data analysis, data presentation, proofreading, concrete and clear writing, and logical organization. This is when a tutor can be helpful.
When I have tutored students to help them with large writing projects, I follow these guidelines:
1) The student's advisors/committee must know about my involvement and its scope, and approve it.
2) Any statistical help I provide must be so well understood by the student that s/he can present and defend it without me around.
3) Any writing done is as much as possible in the student's own words. Anything that appears missing turns into "homework" I give the student, so s/he can learn.
4) I can either teach a student how to use Microsoft Word to format their document to the college's specifications, or I can charge a separate fee for doing this myself. (College's often offer this service as well for students - for a fee!)
Please let me know if I can help you with a large writing project. And for other tutors who do this type of tutoring, please add you two cents as well!