I got a couple auto clones going. Doing well. I have a earth juice root gel and great white i used on them. The heat matt is a good idea. I’m using 1 and i built a little wooden box for the humidity dome i bought. Here’s a pic of my set up. Important to spray the leaves like 8 times a day. Roots developed after 10 days. The cut of the clone doesn’t have to be exact but try to keep that 45 angle. Snip off the tips of the biggest leaves. I eyeball it. I used a florescent light same i use on my seedlings. And kept humidity around 70 80 and temps were about the same. Light cycle was kept close to 16 on 8 off. Day 1 to now.
Have fun and happy growing.
Here is more on my clones if you are interested.