all of my instructions below and do as much reading material as you can for each instruction. You need to make sure that you're downloading the right files and cleaning up.
Just downloading and installing mods with a manager is going to give you crash to desktop most of the time.
Modding takes a lot of practice and there's a lot of techniques to master. Honestly the best thing you can do is a lot of research. I got everything running real smooth aside from neck seams which I need to go back and fix. I actually just bought and modded New Vegas for the first time yesterday. I use mod organizer and highly recommended it.
