Once you have your transfers, the process is simple:
Align as required on your garment with paper between transfer and heat source.
Apply medium pressure for 15 seconds at 150-165 degrees C.
Let the transfer cool and cold peel the transfer film away from the garment.
You can add an extra post-process press for 5 seconds, if you like. This gives a finer finish and gets rid of the occasional stray glue particle.
Nudged the print during pressing and something hasn't sealed? Don't panic yet! Carefully realign the transfer paper and repeat the pressing procedure above, before peeling away the film.