Try not to make any decorating comments in the home if the Sellers are present. What you want to change could offend the Seller - remember they love their home. Let the sun shine in. Open draperies and curtains but also close them before you leave. Dripping water in or under sinks suggest faulty plumbing and deferred maintenance.
Repairs can make a difference.
Loose knobs, sticking doors and windows, warped cabinet drawers and other minor flaws. Who repairs and pays for repairs depends on negotiations. Bathrooms are important. Check caulking in bathtubs and showers. Are bedrooms neat.