I give to charity or the tip. Cannot be arsed with trying to sell things for all the reasons already mentioned.
That's a shame, we've raised a few thousand pounds over the last 20 years by selling our used/unwanted stuff, including books, dvds, furniture, curtains, hobby stuff we've got bored with, even a couple of derelict garden sheds!
A lot of it was selling off our son's stuff, i.e. his cot, prams, car seats, clothes, bikes, scooters, toys, games, consoles, phones and Ipads, etc., which we have put the money into his bank account and amounts to £2,500 so far sat there waiting for him when he needs it.
For our own stuff, we use the proceeds to buy new stuff, and only this year, it's been used to buy a new lawn mower, wide screen TV and a new satellite box.
That's a lot of money to lose for the want of a bit of time and effort to sell it. You get a really good feeling inside when you look at something new and know that you've not actually had to "pay for it".
The key to hassle free selling is get the platform right, i.e. avoid freecycle and facebook like the plague, and research what you've got and what they've sold for (i.e. ebay sold listings), postage costs, etc. That way, you can ditch the low value stuff that won't cover fees and postage or package it as job lots. Also, you need to develop your own "tyre kicker" radar and not engage with them. Lots of genuine/good buyers out there.