It also helps to oil them if you won't be using them for a few days or weeks.
Automobile oil, used auto oil, and mineral oil are all good.
Maybe keep a bucket with some coarse sand or gravel and some oil, them mix it up and plunge to shovel blade a few times to clean and oil it. But it's easier to spray the shovel with water, let dry, and rub with oily rag.
I put mineral oil and/or beeswax and/or parafin in wooden handles, because they get a lot of rain on them.
You can even rub some Johnson's Wax on a steel tool before winter storage. The wax dries to a hard film. But oil works about as well and is easier.
