Clothes - High-end, good condition name brand clothes go in the store/on eBay; lower end but still good quality and condition clothes get bundled up to go to the auction or the garage sale/flea market. Everything else that isn't rags goes to Goodwill/other charities. Retro (80s and before) clothes go on eBay/in the store or taken around to resale shops; usually sell this sort of stuff the fastest.
Smalls, kitchen goods - Straight to the auction. Nicer stuff goes by itself, junkier stuff in boxes.
Small accessories, low-end small antiques/collectibles - Either go on eBay in a lot, in the store for cheap filler or if it's getting overwhelming/is kind of tacky, it goes to auction. If I have enough stuff that is similar to fill a box, I'll sometimes list it as a lot on eBay. Starting bid is enough to make some profit, and sometimes you end up with a surprisingly high sale (a bunch of low-end military junk got me $115 after a bidding war).
Higher end antiques/collectibles - eBay, the store, and where ever it may be relevant to advertise them.
That said, I've taken a few pretty decent antiques/collectibles to auction. It's a promised sale, even if you only get 1/8th the value - and after having it sit around for 6+ months you'll take it.
If you want to get rid of Goodwill-esque junk and still make some money, look up your local auction houses. Hell, go to a few and see what sells and what doesn't. Around here, I usually take my "better" stuff to Big Bear, my unique antiques/collectibles/art to Shipshewana and my junk to one of two small places by me.