I usually do the fitting of the tang in the handle first. Then do all the primary shaping of the handle with the blade fixed in the handle.
Also, i finish the bolstr on the front part completely.
Then i remove the blade and give the blade the finish i want.
Then i glue,fit and peen the blade in the handle. Then wrap the blade in painterstape and carefully finish the handle.
I'm not the most patient guy ever, so sometimes i mess up when doing the final finish of the handle...
This is just the way i would do it.
This is my current WIP. I think its kinda the same thing you are going for?