Do not sweep things under a rug or carpet. The carpet or rug should lay flat on the floor.
If you have pets hire a professional to deodorize carpets.
If needed, replace cracked or chipped ceramic tiles.
If needed, steam clean carpet thoroughly.
If needed, install new neutral-light colored carpet with a thick padding so prospective buyers feel comfortable as they walk on your floors.
Make sure carpets are secure. Stretch and tack down any loose or curling carpet.
Make sure the carpets are vacuumed, free of pet hair and combed.
If you decide to replace a linoleum floor, choose a neutral color that will have wide appeal. Lighter colors are usually best. Use larger patterns in the kitchen to keep "business" down.
If your home has hardwood floors with room-size rugs, get the hardwood into its best condition with fresh non-slip floor polish or other coating to make it shimmer.
Mop and vacuum floors.
Replace worn out vent covers.
Thoroughly clean linoleum floors in kitchen and bathroom.