"3D Printing" is often a marketing term for many different forms of technology. Find out which specific technology you're sponsor/school/machine shop has available to you and what it's strengths, weaknesses, and associated costs are.
I've used
FDM for a school project before. I'd offer tips or tricks, but I don't really have any. We were able to machine the part after printing to make adjustments that our final design called for.