Hrm... Never thought about it. I just do it.

All of my 64-bit Peppermint machines are dual-booted with '10'. Setting them up is easy as pie, and ordinary as shaving or brushing my teeth.
The only difference is the BIOS settings. Some of my machines support UEFI/Secure Boot, and some don't.
I only have a couple of minutes, right now, but I'll give you a broad overview
I start with a freshly formatted (fat32) drive, then install winders first.
Once '10' is up n' running, fully updated, and stable, I reboot into a live Peppermint USB installation ISO. then use GParted to shrink the winders 'Basic data partition' down to a reasonable size. 150 GB is plenty big enough for me.
Next, I use GParted to make three Peppermint partitions. Two (ext4) partitions are used for 'root' and 'home'. One is for 'swap'.
Then, I install Peppermint using the 'Something else' option in Ubiquity, designating these partitions for 'root', 'home', and 'swap'.
Here's a snappy of what it looks like, on this machine...

And, that'll have to do it for now.

Gotta run. BBL