The way I decluttered my house is I went through each room and I vowed to remove one item from the room to donate. Once I started getting rid of a few things it was easier to get rid of more. It's funny how attached I had become to "things."
I still have a lot of clutter, but I go through it every so often to pare it down.
I think losing weight helped, as I shed pounds and started to get rid of non fitting clothing, I also got rid of others things that were weighing me down.