During the process of writing the thesis, you may benefit from discussing the problems and issues of the thesis with other students. Most students will get someone to proofread their thesis before they submit it, but its also a good idea to use each other much more - and also earlier in the process. For example, you could get others to comment on your synopsis, read drafts of specific sections, etc. Having a thesis group can also help you boost and uphold your self-discipline. If you meet up on a regular basis, the group work can help to clarify whether or not your thesis is progressing.
Naturally, it is an obvious choice to form a group with people who are writing their thesis within the same academic area as yourself. The benefits of doing so is that you will be able to engage in and inspire each other in theoretical discussions, help each other find relevant literature, and perhaps discuss specific theorists and books, etc.
However, most people would also benefit a great deal from discussing the thesis with someone who has no specific prior knowledge of the specific field - particularly in connection with the structure of the thesis.