I’m about to start making effects for my weapon attacks using parts, meshes, particles, etc. I was wondering if you guys have any tips or advice to give when it comes to creating the module. (like what it should contain and such)
Howdy! 
Could you elaborate as to what you want to use said module for? Would it be used for easy cleanup, would it be used to damage players, etc.
I’m not really sure if I get the question but the purpose of the module I want to make is to just create visual effects that go along with attacks/actions that the player does.
rainbow trail,fire particles,water,ice,black magic,shiny particles
I see, in that case you might want to add a few functions in your effect either by using OOP or simply going with non-static functions.
These functions should consist of either cleanup functions OR things you might find useful such as setting the size of your effect and so on.