How would one go about making an efficient animation code?

Hey guys, I've decided to make a make-shift animation code, since I can't really afford to pay for animations every time I'd like to make one. I've done this several times before, but I can't help but feel that they're a tad inefficient. My current setup is as follows; I weld all of the body-parts to the rootpart. I then interpolate between two positions for each part, using coroutines to animate them all at once. I follow up by simply dewelding the parts. I'm looking for a new concept, if anyone has any ideas. If you need more info on what I already have, feel free to ask, and I'll do my best to answer. Thanks so much ^^.