Honestly, only one true must: talk to, and ideally interview, a good local real estate professional before you spend a dollar on prep. After years in a house you become hypersensitive to its flaws, and it's easy to pour money into fixes buyers in your market don't care about while overlooking the things that do move the needle. Certain upgrades don't reliably return what you put in, and what a seller obsesses over is often invisible to buyers. Which prep pays off is genuinely market-specific. What helps in one neighborhood or price band can be pointless in another, and a good agent who knows your specific area and price point can tell you which is which. So run the sequence in this order: get the market-specific recommendation first, then decide on repairs, staging, paint, or cleanup. That one conversation up front usually saves both money and time, and it keeps you from doing work that won't change your sale price.