Everyone’s different etc. here’s my routine: make sure you have the content of the course boxed in so that you know where the knowledge you are supposed to know starts and ends. Then sit down and condense all chapters into your own notes, it takes a few hours but it’s the first step. Once you have all the content in short notes, take a break and then read through them and make sure they all connect to the memories of the concepts that you need, i.e. you can get the info you want in your head just from the note you made.
Here’s where it gets harder, start asking yourself reasonable questions for each chapter/subject/concept. Like, say someone wanted to know where this theory comes from, can I answer that? or, say someone wanted me to solve for this given that, can I do that? do a bunch of that for a while for your topics. This is the reality check of how well you actually know the stuff. Use the book to try and answer your own questions all you want but his for me is the stage where you build confidence going into the exam, once you can start answering your own reasonable questions you start to feel good about the stuff. This is hard though.
Last, go through a few old exams from the same teacher giving your exam, get in their head a bit, figure out what types of questions they usually pose and how their problem solving method works or what they usually look for in an answer. Do not study too much the day before, just go over those notes and make sure your memory connects to the stuff the way you want it to, there is usually too little time left to form good memories the day before. Sleep well the night before, be ready for combat on the day of exam.
On the actual exam, leave partial solutions if you can’t solve the issue or answer the questions. Tell the teacher all the stuff “you think” even though it doesn’t give the answer, if you need an answer from a previous question, do the “I didn’t solve it but say it was this, then I’d proceed like this”. Write words, explain your though process, it often gives partial credit. If you don’t know the answer but can exclude alternatives, write that and why, it could give partial credit with some teachers.
Aferwards get drunk, hate life, consider becoming a sea pirate. Good Luck.