Step 1: Don't Iron with Your Eyes Closed
It's just not a thing, people. You'll burn yourself or ruin your shirt. Or both.
Read more about the dangers of ironing with your eyes closed.
Step 2: Use the Right Temperature
Don't try to iron your delicate lingerie with the same settings you use for your favorite t-shirt from college. It's just not worth it.
Learn more about the subtleties of temperature control.
Step 3: Don't Over-Iron
You're not trying to create a tablecloth, folks. Just smooth, not... well, not... tablecloth-y.