First, a poster is NOT a paper. A poster is a visual presentation of the most important and interesting features of your work. 

TIME. Expect people to spend ~3 min at your poster before deciding if they want to stay or leave. Aim to present the main message of your poster in 5min. If people stay, you can then go into detail by answering their questions.

A quick presentation means you communicate to more people. And people will leave with a clear message. And they are more likely to remember you. 

DETAIL. A good poster has ONE message: one key prediction, only the key methods and only the results for that singular prediction.

Your project may have had many great aspects. Methods may have had interesting details. But putting them all in a poster will backfire. Choose what is your most important message and concentrate on that. 

TEXT. Cut down as much as text possible. Subtleties of paper writing are not for posters. In a paper you may say “Many studies have considered A to be B”. In poster you should say “A is B”.

FIGURES. Max number of graphs = 3. Take out figure details as much as possible. Only keep the most important and most critical things. Figures should be easy to see from a 2-meter distance when printed.