Uncovered tank

[blueridge]

I have recently come back to the hobby after a 10-12 year hiatus (school, etc). I purchased a 50g rimless, cube setup from someone locally. What are the best practices for preventing fish from jumping. I always used to keep my tanks fully covered to prevent jumping. However, rimless and uncovered tanks seem to be "in" now. What measures can be taken to mitigate the risk? What species are poor choices for an uncovered tank?

Thanks