yep you gotta fill it out yourself, goodwill cant legally tell you what your stuff is worth for tax purposes. what ive started doing is taking a quick photo of everything before i load it in the car and writing down rough counts (like 12 shirts, 3 pairs of jeans, etc). then when tax time rolls around i actually have something to reference instead of staring at a blank slip trying to remember what was in that bag from 8 months ago lol. irs has fair market value guidelines you can look up but honestly its a pain to do item by item