I have been trying to get rid of a lot of excess things in our house. I have been donating clothes, appliances, food we won't ever use, and also my CVS extras that I don't use, to my local Faith Rescue Mission. You drop it off and they give you a ticket to have proof for your tax return and you put in the value of the items. Of course, if you do it in an unreasonable amount, you might get questioned, so please be honest in the value of your items!
You really don't know how much 'stuff' you have until you go through and weed things out. Donating is a great way to not only help others, but get credit for it on your end too.