When I bought my SJ's and CWB's 4 or 5 months ago the saleman there told me to try on a few different sizes and then order the size that fit the best. I only had SJ's to try on but I found the size 11.5D that fit the best. He told me to make sure the arch support was in the right spot and then had me stand on a step with the boots facing down to see if my toes got crunched.
Once everything was like he said it should be I ordered an 11.5D and they have fit quite well. They are just slightly loose in the heel but nothing to worry about. I have ducks feet so i'm not surprised but they are snug enough in the heel to where when i walk around in them I don't get any blisters or anything.
The CWB's work with the medium weight socks I fitted in as well as thin socks. The SJ's work best with medium to thick. My salesman told me it's best to fit them with boots off the shelf than send tracings because White's can always say you did the measurements wrong. Then you're stuck.
When it comes to bakers I think doing the tracings is a good idea since they guarantee the fit and will send a pair for you to try on once they get the tracings.