Just bought a heat press - any hints or suggestions [View all]

I have used an ordinary iron to transfer Teddy Bear images to t-shirts for granddaughters, years ago, this was fairly easy. The images held up well to washings, kids wore the t-shirts many times.

I have a huge collection of vintage Texas postcards and thought I'd print some on t-shirts for Christmas gifts. I have scanned images and edited them in Photoshop. I have t-shirts, ready to print them using the new heat press.

Anything I need to know to keep from messing up? If they turn out okay, I will post some images. If they don't I will be bummed out.