Install a shower basin and floor drain in your mudroom to collect wet footwear. Add a wall faucet and flexible hose attachment for rinsing off mud and debris. (It's also handy for a quick pet bath.) And don't forget to include a fold-down bench for putting on shoes or stacking a few cleanup towels.
mud room-- I don't like the way this one looks but I like the idea of each person having their own space in the "mud room" that way everyone can have their space that they have to keep as tidy as they feel necessary (so I can have my clean space and quit nagging my husband to clean up all his stuff!)