It's true that showers are one of the worst things for your feet - there is a great tendency to overlook them.
Most important is to physically wash them, if you can't balance on one leg sit down in the shower and do it. Then there is the drying, too many people just let them air-dry, then some bits, especially between the toes won't dry before you put your socks or shoes on, if you are in a hard-water area there will be a build up of calcium salts which may cause other problems too. A water softener will probably help.
So dry thoroughly and use a cream, any simple cream will do, but not too greasy or oily or your foot may start sliding around in your shoes and that can feel quite uncomfortable. Fancy expensive creams aren't necessary unless you are treating another problem, they simply doubly ensure they are dry and add a fine protective layer.
like every thing in life you only get out what you put in, so if you want to care for your feet well you'll need to soak them a couple of times a week, a large washing up bowl is all you'll need. what to add to the water - I've used anything from TCP (diluted as instructions) when treating fungal nail infections and cracked skin to Epsom Salts which I'm trying now and are a great low cost way of softening your skin and may have BP reducing advantages too.