Hi Gregory:
I think the more variety the better. Tradionally, a final, mid-term and quizzes make up the majority of a grade. But it doesn't have to be that way (unless your institution says so).
Projects, written papers, creative arts such as models, PPT's, poster boards, applications, lab skills, discussion - each of these could be categories that contribute to a grade.
We want to measure to what degree did the student meet or not meet the course objectives. There are may ways to determine that, some very creative.
Regards, Barry