Trail Plugin Help?

I'd like to work on designing my own player trail plugin, but I don't really have a starting point. Can someone please give me an outline for the coding I would need to design such a plugin? Also the four most important effects I will need guideline-wise are how the embers spread out and look on FunnyFoots, and on the same plugin how the endertrail looks like that sort of effect. Also, there is a straight-line trail of hearts on the heart part of it, and I will need to know how to get the effects to go in a line like that. Any help will be appreciated! Sorry, I am super new at this. And I am not asking to copy your work at all. If you post me an outline that includes your own trail, I promise to replace it with my own information. I really just need general help.