Wiping your feet holds much dirt out.
Ventilate often.
Keep the bin clean, close or outside.
Damp cloths, sponges, towels are the biggest germ carriers: frequently wash and dry them well.
Clear and clean the kitchen regulately, also fridge and cooker hood.
Use kitchen equipment only for cooking.
Keep workplaces, tools and cutting boards separate for hot and cold preparation, fish, meat, vegetables.
Wooden planks and spoons are porous, wash them immediately after use.
Keep foods below 4°C.
Use well-cooked food (especially when re-heated).
Eat fresh things and don’t keep them too long.

As a child I lived in an old square farm. A small pit had been laid in the ground in front of the front door. There was a steel grid over it. It acted as a mat. Very handy for kicking and scraping soil and mud off your boots or shoes. The hole was shoveled once or twice a year. What came out was some kind of compost. Very handy but I have never seen it elsewhere.

It helps to avoid dirt in the house. Just like the multi-culture habit of taking off your footwear when entering.

The outer skin cells are replaced every month. You lose 25,000 chips per minute, a million per hour.

"If you don’t clean your house for two months, it will not become dirtier anymore." (Quentin Crisp)
"You should take a bath!" "I do this every day!" "Take clean water!" (JW Besouw)