Keep Polishing your work for a First Class DegreeAssuming you follow my advice and work ahead on your degree course, there will be plenty of opportunities to tweak and revise your work.
Read and re-read the original assignment brief and be sure you have every item on that brief.
Ensure your word count is correct (if stipulated in the assignment brief).
Get your work proof read as often as is practical and keep polishing and refining your work until you are happy it is the best it can be.
Once the bulk of your work is complete, you should find this a relatively easy process which can make a big difference in terms of presentation, the flow of your writing and the overall impression your work gives to the reader.
Do not make changes for changes sake, there is a danger that you can actually make things worse if you meddle too much, so exercise some restraint!