I'm one of those naturally minimalistic people. When I was 13 I ejected everything out of my bedroom, except for a mattress, a footlocker, and a bookcase. The footlocker held all my clothes, the bookcase had my entertainment, and the bed was for sleeping. I was in heaven.
Here's what I've observed, being naturally on the minimalistic side of the divide. I'm ruthlessly unsentimental about most physical possessions. Lots of people seem to keep items that may be useful in the future. Or they keep an item because they like the person who gifted it. Or they think getting rid of an item will negate the memory attached to it.
I keep things because I like the item itself. It's either useful, or beautiful. Everything else I get rid of.
So, pick up everything in your house, and think "If I lost this in the fire, would I feel any true grief? Any true inconvenience?" If the answer is no, then get rid of it.