Hello - I was in the same mode you are in a few months ago. I was trying to sell things, but it was a ton of work and effort and had little return rate.
So i researched donations and have now donated over 1K clothes (20 years of stuff), and well over 1500 books. Clothes go to Salvation Army, and I track each piece and put in the the guideline amount (from Salvation Army website) of the value. So this is a win for me on tax deduction, and the salvation army wins as some of the clothes were NWT or hardly worn etc. (Changes in job resulting in changes in dress code for work, then back to suits etc. resulted in a ton of clothes, never mind going from size 6 to 10.)
The Books I donate to a "Literacy America" bookstore, where its a non profit, they sell the books and use the funds to teach people to read. Since I find reading to be a real pleasure, this feels great to me, and people are really benefiting from this. I have cleaned out the books after moving. Last year I donated the first 1000 books, this year the second. Another tax deduction and the reuse of the books is terrific. Next year im donating my old VCR tap collection, some books on tape etc.
This all requires some tracking, yes, and my tax return will have a list attached with all my non cash donations listed out, but its no more work than the attempted selling etc., and frankly I feel like its all getting reused well.
(For those interested - I track by catagory
Clothes - type of garment, color, size, condition, name (Ann Taylor, Brooks bros, etc,), work, gym or casual, the suggested amount
Books - Author, title, size (small, med, large), type (hard, soft or paperback), condition. In notes I include if its a first edition, has dustjacket etc. I put the amount the used bookstore sells the book for as the amount.
various other things I have also donated to the bookstore (some office supplies and the like), and then the rest I have cleaned out on freecycle. No tax deduction there and no money, but no real hassel either. I have had some success selling large groups of music CDs on craigslist, for $2 each, "must take all" type thing. Good luck.