If you are in academic medicine , you are familiar with making posters for research forums. Based on the dimensions allowed, the content is usually in 3-4 columns. Everyone has a slightly different approach.
This year SAEM is offering a unique opportunity for poster presenters at this year's Boston annual meeting. They have a a professional printing service where you can upload your poster online, have it printed in Boston, and then pick it up at the meeting site. You'll have to carry it back home though.
Even if you aren't using their printing service, this is a great way to see how professional posters look. There is a menu of various templates that anyone can download for FREE: