If you have central heat and air conditioning, especially if you have registers on the floor, it is DEAD SIMPLE to replace the floor vent covers with something that has more personality. As in, no tools required for floor vents.
Life is Great in a 31 by RV Maintenance Monday: DIY Frugal Floor Duct Vent Covers and Stove Top Cover. Buy a plastic scrubbie bath puff and undo it. Cut it into pieces that you can put beneath the vent to catch debris.