With any coursework, just do what the teacher tells you to do. If you have a good teacher, they'll outline exactly what you need to do to get top marks. If you don't have a great teacher, go on the spec and look at the mark scheme. Tailor your exact piece to the mark scheme. Don't try and write anything fancy or whatever, just do what the markscheme says to do.
My next point is a bit controversial, but a lot of people cheat in courseworks, whether it be minor things or big things. My estimate would put it at around 50% don't follow all of the rules exactly, some with even school supporting them in their cheating. If you're sure you can get away with it, feel free to use underhand methods. eg. For history coursework, technically sources can't be taken home so people can't write their stuff at home, but when the teacher left the room everyone I know (obviously not me) took pictures of the sources and just wrote the entire thing at home and either memorised it or brought it in with them and handed it in.