Tool
Should I keep this?
Hold the thing. Answer four questions about it. You will get an answer rather than a framework, because the deciding is the part that is hard.
What are you holding?
When did you last use it?
If you needed it next year, could you replace it?
So why is it still here?
One object at a time is slow, and that is fine. The point is not to clear a room this afternoon, it is to stop the same object being picked up and put back down every time you try.
Common questions
What is the 20/20 rule in decluttering?
If you could replace something for under about twenty dollars and in under twenty minutes, you do not need to keep it for the day you might need it. It applies to most cables, spare kitchen items and duplicate tools.
Should I keep something expensive that I never use?
The money is already spent and keeping the object does not recover any of it. Selling recovers something. The only expensive items worth keeping unused are genuinely irreplaceable ones, and those should be stored properly rather than left where they have drifted.
How do I declutter sentimental items?
Edit rather than cull. Keep the single best object somewhere you will actually see it, photograph the rest, and let those go. The photograph keeps the memory; the object was only ever the reminder.