Domes & Cylinders

I would do the dome before baking. Roll your dough out about 3/8 inch thick onto parchment paper. Roll it out into a big rectangle a little larger than the diameter of the bowl you will be using. Then put your bowl rim-side-down onto the the rolled gingerbread and cut around the rim of the bowl. Remove the bowl and the extra gingerbread. Thoroughly grease the outside of the bowl. Then lift the parchment paper and your dough circle and quickly flip it over onto the greased bowl. Smooth out any ripples and lift off the paper. You might need to make a nip or tuck with a knife to get a completely unrippled surface. Bake the bowl/gingerbread as you would normally (perhaps a bit longer - maybe 30 minutes or more). Let the gingerbread cool completely before taking it off the bowl.

Cylinders follow the same basic principle, but you need to find a cylindrical object that can be baked. Empty bottles or heavy cardboard tubes would work. Wrap cardboard in foil, grease the foil, and make sure that the tube doesn't touch the sides of the oven or any of the elements. The cardboard won't burn at normal baking temperatures. (Just make sure that your oven doesn't have a wildly hot hot-spot.)