I've found that reviewing existing projects has helped me find errors of all types, expand anchor and keyword lists, and basically see what else I'd like to change since starting the project. I can also focus down more on certain engines, keywords, anchors.
Also reviewing the Project>>Options and >>Article settings has been helpful, as over time I've used various settings with GSA-SER projects, checking it all out as I went along.
Now, I'm going back with more experience and seeing some projects could have been set up better, starting with those I did when I first started earlier this year. I'm sure I'll do the same again, soon, and see even more things I could get better.
But point is, rather than do more work always, it's def beneficial to also refine and further craft what's already up and running.