If you're using an Easypress, we would recommending increasing the temperature 30 degrees from the transfer temperature for your HTV.
If you're using an home iron, make sure the steam option is off!
We would recommend starting with Siser EasyWeed, as it's the most user-friendly product! It's available in a variety of colours.
Don't forget to mirror! Most HTV's have a built in carrier sheet, which is like transfer tape, it helps you keep your design lined up together.
Always do a test cut! Do a small square in the corner of your material to ensure it cuts through properly, and its the right side of the product. It's always better to do a small test cut, than ruin an entire sheet of vinyl!