Well, no matter what, we seem to track in a lot of dirt and gravel. We have the GlowSteps, as I mentioned above. And they stay outside -- they are mounted below the door.
But we boondock in messy places -- ice, snow, mud, you name it. So we keep a boot cleaner near the front door, and a stiff whisk broom, and an astro-turf welcome mat.
None of that stuff works perfectly, but we can fool ourselves into thinking that we are doing our best to hold back the mess.
When it gets really bad, we have to take our boots off before coming thru the door. Like the time we somehow ended up in a cow pasture . . . .