Students often find it difficult to metabolise the rules behind scientific writing. They may confuse Methods with Results, or describe their study area in the Discussion section -- something that may horrify the expert reader.
The reason why many students have such problem is probably simple: nobody ever taught them how to do it right.
Then just consider a D.I.Y. approach: it may do miracles here. A simple Google search may come to your rescue. Digit something like "how to write a scientific paper" and see what pops up.
I just tried it and the following site appeared on the top of the list:
I haven't explored any further, but this first hit seems to be good enough for most problems faced by students when the time comes to write their thesis, or their first scientific article.
Happy reading, and then happy writing!