Get a heavy iron.
I had an "aha" moment recently, when I realized that not everyone knew that the weight of an iron does half the work. A group of friends were over at my house, working on a group quilt for charity, and one commented that my iron was the heaviest she had ever used and another commented that it was also the best she'd used for pressing. It wasn't until after they'd left that it dawned on me that neither of them knew that the two were related.
Irons work through heat and weight. If an iron was heavy enough, you wouldn't even need the heat, but an iron can't get hot enough to press without burning unless there is some weight, too.
I hear the cries already of "but I'll get tired if I use a heavy iron!" That's why the iron also needs to be comfortable to hold and well balanced. Besides, when the iron is on the fabric, you aren't holding it up -- you're letting the weight do the work. I actually get *less* tired with a heavy iron, because I don't have to press down with the iron.
Okay, I'm off my soap box now. :)