I just made a poster for a conference and would like to share a few tips. Given that posters are gaining popularity in econ programs and business schools, hopefully someone will find my tips useful.
In addition to the advice from professionals, my tips are as follows.
1.        Use the powerpoint template designed by professionals. Avoid starting from scratch can help you save time. The originality comes from your content, not your poster design.
2.        Make everything using the powerpoint. For example, I have pictures from excel. Do NOT take a screenshot and then paste it to powerpoint. It looks bad once you zoom in. Instead, just copy and paste the graph from excel. Then the picture still looks good after you zoom in. Similarly, write the math formula in powerpoint using insert function or mathtype—no screenshot. My biggest lesson is that screenshots look fine on your screen, but poster will magnify whatever small errors you have.
3.        Avoid busy posters. Use some words, graphs and tables to make your point. Do not copy and paste your thesis. Be concise.
4.        Leave enough time for the job especially when you are making a poster for the first time. I already had the paper and powerpoint presentation before making the poster. So I thought it should be quick, but I was wrong.
Professional advice attached. It is from a US website. You choose your local store.