Right now my current way have producing terrain is very slow and I need tips on how to make terrain faster.
All I do is make big circles for where the terrain goes and fill in the circle. Kinda like this. ↓
So if there is a faster method of producing nice looking terrain tell me. 
(If I don’t respond check the CST/CDT timezone for what time it is.)
There is an option in the terrain editor to generate random terrain. Maybe you could use this and then go over and change any things that you don’t like. Here is the Roblox documentation guide that talks about terrain. It tell how to use the generate tool. Terrain Editor
Well, I’m making a map for my game and creating by “hand” I guess. So there is different regions of the map that I want the player to explore but Roblox’s random terrain looks “ugly” which has big sploches of say for example snow on a hill.
You can turn off snow so it won’t generate that.
I know there is a region option to were you can go quite a long way, but not in a circle, but instead in a big rectangle or square.
That is the only other thing I know you can do, other than that there is no other fast way to generate terrain.
Height maps man, Height maps.
Plan out your map in a painting software, I recommend Krita cause its like Photoshop but free, and then create a black image, then gradually draw layers, while trying to blend them
The higher you want the terrain the lighter it should be, the lower the terrain the darker that part of the image should be.
Something like this:
