To allude to a StackExchange thread, The problem with scientific posters is that they look like scientific posters. Defining characteristics include a lack of whitespace, unattractive borders, poor colour use, and poor fonts use. Using a recent scientific poster of my own as a example, I explain how to create a clean, elegant poster with minimal artistic talent.
The little things matter; for example, a typo. In theory, a typo is a minor mistake that makes no difference to the meaning of the writing. In practice, if you’re like me, your opinion of the quality of the rest of the work decreases. Moreover, you may inadvertently seek out further faults.
The same can be said for figures: poor attention to detail will spoil an otherwise perfectly good plot. For this reason, here’s a short list of easily adjustable details that will improve your figures.