I have done this for the past few years and it has really helped.
Three years ago I resolved to finish everything I started that year (sadly for a couple of projects, that resolution wasn't retroactive and I still have a couple of nearly complete sweaters just sitting...) It was a great success and felt great to complete so many things that year.
Two years ago I decided that maybe gauge swatches weren't really over-rated and promised myself I would make one for everything I made that year (except socks.) Do you know what happened? I started making things that fit me perfectly instead of getting one or two things that fit and loads of items to give away!
Last year I decided I would wash and block everything before wearing it and I LOVE the results. I just set up some fans to speed up the drying process and between having garments that fit and are nice and soft and ready to go I am very happy
Not sure what I will do this year. I have already decided I need to finish all of my have done projects sitting around the house in the next month but I don't know what else I could hold myself to that would improve my knitting.
Any ideas? Anyone want to join me?