Start with light and paint
Clean interior glass, replace dead bulbs so every fixture in a room matches in color temperature, and remove heavy window treatments. A room that photographs bright reads larger than the same room photographed warm and dim.
Paint is the highest-return item on the list. A bold accent wall, a nicotine-tinted ceiling or patched drywall that was never repainted will cost more in buyer perception than the repaint costs.
Fix what a hand touches
Buyers test doors, handles, faucets and cabinet hardware without thinking about it. A door that sticks, a loose towel bar or a running toilet reads as deferred maintenance across the whole house.
Re-caulk the kitchen and bathrooms. Failed caulk is the single most common thing photographed in close-up inspection reports.
What is usually safe to skip
Full kitchen or bath renovations rarely return their cost on a fast listing timeline. Neither do landscaping projects beyond cleanup, edging and mulch.
Replacing functional appliances is usually not worth it; cleaning their interiors thoroughly usually is.