1. Use an old scrap grip panel (preferably) made of the same plastic to practice on... don't use too much heat, develop a time/pressure repetition.
2. Play with different tip shapes and angles of placement, until you find something you like.
3. Did I mention, don't use too much heat?
4. Lay out a basic pattern before you start.
5. Take your time.
6. Post photos of your work and a description of how you did it.
Cheers,
C