If it's been a while since you last looked at the literature (or a specific area of the literature), here is a very quick way to find recent relevant papers.
Pick a few (5-10) important papers you already know are relevant to your work or the area you want to look at. It's highly likely that anyone doing similar research will cite some of the papers you already know about. So if you look up those papers on the journal's website and check the "cited by" information, you can find some recent gems.
This is especially useful in the time between submission and your thesis defence.
