Hey Kathyk !
I usually do a really good job with a cloth wiping it down. I’ve read that varnish contains rosin so the rosin from your bow really wants to bond to it so rub it off ASAP. If you can’t or some is left over there is rosin removers. I bought some rosin remover for my strings cause after a couple weeks they get really sticky. I am careful not to touch the wood cause I don’t have a plosih. However from what I’ve read most people do jot even polish their instruments. One old luthier was breathing heavily in the instrument and literally rubbing his vapour onto the violin to polish it. You may be able to use some rosin remover for a few spots but id be worried it would damage the varnish if it does infact contain rosin as well. What do others think ???