DIY projects that add the most value when selling focus on cosmetic upgrades like fresh paint, updated lighting, and clean grout in kitchens and bathrooms. These low-risk improvements enhance curb appeal and make spaces appear move-in ready. Buyers pay attention to bright, clean, and well-styled rooms rather than hidden structural fixes. Avoid complex work that requires permits or specialized skills, and invest your DIY effort where buyers notice most to boost home resale value effectively.