I have a variegated willow and I do nothing with it. Mine usually gets some winter kill on it tho and I just prune that off in the spring. I don't have a smoke bush but I don't think you do anything specific with them.

In regards to the Smoke Bush, do nothing at this time of year. Be prepared for this one to emerge late - ie, don't expect it to leaf out in the spring and wait until early summer for leaves to start showing. Lots of folks think they are dead from the winter when their Smoke Bush doesn't leaf out when all other trees and shrubs do and make the mistake of pulling them out and replacing. (I did this... :O(