Unjumbl
A list of forty things is hard to start. One thing is easy. Working from a single item at a time keeps the whole pile out of your head.
A long checklist makes you look at everything at once: what is left, how far you are, what you should do first. That is the part that stalls people. When only one item is in view, the question gets small: what do I do with this?
One item at a time still needs a boundary, or it never ends. Choose a shelf, a drawer or one corner of the floor, and decide you will stop when it is done or after about 15 minutes. See the 15-minute timer.
Take the nearest item. Give it one of a few outcomes: keep, donate or trash. Say it out loud if that helps. Do not look at the next item until this one has a place.
Put the item where it goes: back on the shelf, into the donation bag, into the bin. The decision is not finished until the item has moved. Then take the next one.
Some items will stall you. Give yourself one skip: put it to one side, keep going, and come back to it at the end. If it is still undecided then, ask a concrete question such as "would I buy this again today?" There are fifteen more in keep or toss: 15 questions to ask about any item.
Want it one item at a time on your phone?
Unjumbl is a declutter app that turns a photo of a messy room into small 15-minute zones. Its focus view shows one item at a time with a big Done, next item button, a timer from the zone estimate, and a Skip for now option.