The phrase “sort out the house” describes a large ambition, not a task you can finish this afternoon. Give yourself a smaller boundary: one drawer, one shelf, or one category of items.
Choose something that is useful but not deeply sentimental. Old cables or duplicate kitchen tools may be easier than family photographs. Set aside a short period of time and make a clear space where you can see what you have.
Separate the decision from the destination
First decide what you want to keep. Then work out whether the remaining items can be donated, recycled, sold, or disposed of appropriately. Check local acceptance rules before loading the car. A donation pile that never leaves the hallway simply moves the problem.
Do not make assumptions about what relatives want. Ask, give them a reasonable opportunity to respond, and agree on a collection plan. A photograph of an object and a note about its history may sometimes be more useful to them than the object itself.
Allow a small undecided box
Some choices need another conversation. Keep those items together, label the box, and set a date to revisit it. The box should give a decision time, not make it disappear.
Finish by putting the things you are keeping back in a usable arrangement. One completed space is evidence that you can make progress without settling the entire future at once.
