As you are gathering your donation items together:

Make a list of the items as you go. You can list everything separately or break it down into groups, such as:

5 pr of ladies pants
6 ladies shirts
4 mens pants
1 box of misc toys
1 end table

Then, write an estimate of the current used value of the items.
You can basically figure a price of what it might sell for at a thrift store:

Hold on to this list, (Do Not Put it With Your Donations)

Attach it to the tax receipt which our driver signs and dates and leaves at your residence when he picks up your donation.

Keep the receipt and your list together, and file with your records when you use it to claim your deductions on your tax return at the end of the year.

Please understand that we cannot provide tax advice, and highly recommend that you check with a tax professional if you are seeking tax advice or need further advice on proper valuation of your items.