I donate everything. I use Goodwill and the local women's shelter.
ONE time I went to a resale shop with $50+ outfits hardly worn and they offer $2 or so... no stains, some still with tags. No thank you. They offered us $50 for a $500 crib that was used with our daughter from birth til 17 months. They didn't think we'd reload it back into the car but we did and then donated it to the women's shelter.
ONE time I had a garage sale and the same thing, I wasn't asking $50 for my outfits, etc, I was asking about $10 and less (mostly way less) and still the people who came by wanted to dicker so much I told them all to leave, closed up my garage sale and donated everything to Goodwill.
I don't care for garage sales because it is a prime chance for someone to case out your house, sneak in to the bathroom and/or rob you blind while you are there watching. No thank you.
After my experiences, I donated everything and took advantage of the tax deduction which will offset your other costs as well.
On FB, there is a local resale page which is private with a bunch of local moms and they sell a lot of children's things for very low prices. For instance, not much is over $5 for a piece or an assorted bag. Sometimes someone will post a nice outfit that was only worn once or so and get a little more than you would at a garage sale, consignment or resale shop.
My time = $$$ Is it really worth your time?
Best of luck to you!