Heat Gun? For what?

Just start at your shear. Are you doing an inside Stem and finishing it with an outer stem piece)s)? What are you building? You'll be able to bend it right up to the tip of the bow (usually). What sometimes happens is the you will have to do a few filler strips at the bow because the amount of strips won't fill the entire bow area. Do you know what I'm talking about? You probably have a book or instructions?

Most plans have shear markings and it's as simple as that. Run it right down to the bow tip and stern tip. Strips bend really easily especially when you start fastening them in the center of the boat. Once you start you'll see that it's pretty easy. It's always a little nervous getting started. Most important thing is to sight down those forms and makes sure your bow and stern forms and in perfect alignment. Other than that, with strip building you can't screw up.