If you are on Facebook, it is well worth joining your local selling pages. This means that you are selling to people locally, so eliminates the need to post items - people either come & collect or meet you somewhere or you could offer delivery for a little petrol money.
I find that bundles of clothes for children work well, or 'posher' (branded) items. Also, children's toys, bedroom furniture. Adult clothes do not sell so well unless they are branded (eg Nike, Ralph Lauren etc). That said, I have sold some size 12 tops for a teenager (6 for £5 - Next, Warehouse etc), so worth a try.
Also try Gumtree. Again, free to advertise with photos & local.