I bought my house in July 2014. A core requirement for the house is a large enough garage such that I could have serious space to do wood working.
The first phase consisted of cleaning it up, so I power washed the concrete. It had years of caked on dirt, and I was able to get it all up with my power washer. I spent several hours smoothing and adding spackle to the walls since there were visible seems.
For safety, I wanted the walls and ceiling to be white.