I made a poster format in latex for my presentation last year at the Society for Mathematical Biology annual meeting. This paper was just accepted for publication! 😀 Check out the source files here.
This poster is 3’x4′. Some of the formatting is a bit creative, but in general I used the tcolorbox package to make the gradient title bars and smaller section bars. You need the style file found here.
Check out my post on how to make fabric posters.