Hey Dev Forum users! Here’s a small and straight to the point trick on how I personally make terrain using Roblox’s fantastic tools!
Download Part to Terrain Plugin
Create a shape with parts/meshes
Move the parts where you want it
Erode and sharpen to tidy it up
!END RESULT!
Nice! I was looking for a way to easily to terrain
Been working with the plugin for months an I have no regrets using it. 
This is a simple, yet efficient way of making terrain. This deserves to be in my bookmarks
man just solved all my issues with a plugin I already had 
I should use that more
Gap fill helps alot. It allows you to fill gaps. I was already doing this though (You got that right about it being the best and easiest way.)
Its a life safer i remember using the snake method which just takes too much time
