MineMe

First of all, you need to understand how MineMe finds out which kind of mine you want to create (Below only applies when you create a mine through WE):
When you type /mm create (MineName), it detects your selection type, in case your selection is of the type Cuboid, MineMe thinks: "Ooooh ok, so his selection is a Cuboid, so obviously he wants to create a Cuboid Mine!"
Then, MineMe will get the selection area and automatically create the mine.
Now, when you want to create a Circular Mine, you need to change your selection type, to do so, type //sel cyl.
Ps: Just in case you're confused about the names Circular and Cylinder, they means basically the same thing (Same, but different, but still same), I just think Circular sounds fancier.
This basically tells WorldEdit: "Hey, I want to select a circle now!" and magically WE will change your selection to a Cylinder type.

Now when you type /mm create (MineMe), MineMe will think: "Hmm... His selection is now a Cylinder, so he wants to create a Circular Mine!"
And mine me will again get the selection area and automatically create the mine, but now since it's a cylinder, the result will be a circular mine!
Please note that MineMe will use the X radius of the cylinder as the mines radius, since you can't create Oval Mines (For now), which means if you have a Cylinder Selection of 6 X radius and 4 Z radius, MineMe will create a mine of radius 6!

I personally think creating mines through config files is way easier, but hey, we're all different
First of all, you need to create a mine file, AND FOR THE LOVE OF GOD NAME IT THE EXACT SAME NAME OF YOUR MINE NAME!
You can use this as a template:
Now, each mine type reads the config file differently, although there might be a few similarities:
First of all: Every mine config requires the type parameter, no exceptions. Note that either mine use type: CUBOID or type: CIRCULAR, so remember to change that! If you don't change CUBOID to CIRCULAR, MineMe will try to load the config as a CUBOID mine, and you'll get an error.
The first difference you'll notice, is that CuboidMines have X1, Y1, Z1, X2, Y2, Z2, while CircularMines have X, Y, Z where:

• X = The mine's center's X coordinate
• Y = The mine's center's Y coordinate
• Z = The mine's center's Z coordinate

These 3 coordinates will be the lowest center point of the mine, which means this is the reference point where the hole mine will be created.
CircularMines also have 2 other needed paramaters:

• Height = The mine height starting from the center
• Radius = The radius of the mine

Height is an Integer! Which means you can't put decimal numbers (You can, but it might be more prone to bugs)
Radius is an Double! Which means you can put decimal numbers, although Integer numbers are fine too.
After creating this file, put it into the mines folder (if you haven't already), type /mm reload, and the CircularMine will be loaded