Full coverage fenders would help a lot still. Also if your fork is rusting try painting any places the paint is missing, if this is a suspension fork with steel stanchions there is not much you can do other than trying to keep a thin layer of grease on there. Also if you are using a wax based chainlube switching to an oil based one would help it stick around much longer. A guy who posts on here regularly FBinNY makes Chain-L and that would be a great choice but lots of other options work well too as long as it is oil. Don't want to get another chainlube debate going....

The key to fighting corrosion is to keep everything well lubed, bare metal painted and washing the bike more often is not a bad idea either although it is something I do not do around here since they do not go too crazy with the salt usually.