I did this for a couple when I was in high school. They had posted an ad in the schools paper wanting a well organized teen to come organize and declutter the house. The husband was handicap from a car accident and the wife was working a lot. They asked for a reference letter from 2 teachers. They loved the results and gave me almost double the agreed amount.
I went from a 2000sf house to a motorhome. I gave away all the furniture, housewares, and all of my entertainment dishes to friends and family. Even keeping what I thought was bare bones basics, I've had to cut that way down or swap for "RV size". . When I think of all the money I spent on stuff for that house it makes me sick. My 3 rules in a small space: 1 a place for everything and everything in its place, 2 if you are too tired to do anything else, at least clear off the kitchen counter, 3 if it hasn't been used in 6 months you don't need it!
We are going through decluttering right now. We have to make a decision if we want to move to my father in law's house and sale our house or rent it but with two houses full of things it's a huge amount of stress. I like the minimalist lifestyle but my husband likes the cluttered style. Drives me crazy. I buy too many high end designer purses but rarely use them that is my weakness. Too much.