Go to heroforge.com and create your mini as much as you like, having the following in mind:
Once you're done, click on the arrow next to the name of the mini
Click on Share
After hitting accept on the message that appears next, copy the link and send it over to me.
Go to the following links, pick a frame and include it with the share link:
Head over to your favorite image search tool (like google) and pick a cool image that will serve as background for your mini.
Lastly, pick colors for your mini, they can be as vague or specific as you'd like, but do keep in mind the following:
Send everything to me. What's everything?
In this example, 1 is the frame, 2 is the background and 3 is the colored mini