I'm going through the same process at my house! Here's what I've been doing with my things:
1. True junk - toss it. No one wants it, it's cluttering your life, you'll feel better handling it decisively.
2. Things in good condition, that have a moderate sale value - post as you go. (see options below) Put it up for sale for a reasonable amount of time (I do 2 weeks - initial post, & if no response/sale, a second post after a week. Beyond that, it's not wanted by anyone else, therefore no $$ value, so then it's time to donate it.)
3. Truly valuable items (art, collectibles, specific name brand items, etc), large quality furniture pieces - attempt to sell as in #2 above, but make sure you do some research ahead of time to find out what something is worth. Consider using a consignment shop.
4. Avoid a rummage sale, unless you have a place to store all of your items, you live in an area where there is a lot of traffic to draw shoppers (ideally in a neighborhood that has a scheduled rummage event), and you have a ton of time to gather all your items together, put them out, price them, protect them from bad weather, secure them at the end of the day, spend an entire weekend sitting out trying to sell items, only to have people try to bargain your fair price down to 75% off... see my point? Not worth it, IMO. (FYI - a friend had a rummage this weekend, great location, neighborhood-wide with multiple families participating, 3-day event... I brought some stuff over, could've made >$100 if it all sold. I got $24, for 2 items, neither of which was full price. The other items didn't even have interest... only because my friend had the sale & offered to let me hock a few wares did I bother to participate...)
How to price items for option #2:
When pricing your items, make sure you price them at what they are currently worth, not what you paid for them, or what they would cost to replace with new items. For example, a set of everyday dishes for 4 would run $30-50 in the stores. Place it for $10-20 (depending on name, quality, age, condition) to make some good turnover. Remember, you are giving yourself some time to see if you can make some $$ & let someone else get use out of items in good condition - this isn't a time to hold-out for top dollar. I recently sold a bedroom set for $120. For an extra $25, we delivered it to them (I was moving out of my apartment anyway...) It was in OK condition, not real wood, with a crappy mattress/boxspring included. But it looked nice, & I had over 20 people respond - I probably could've gotten $250, but if I had PRICED it at $250, I would have had few, if any, responses, & might have had to find somewhere to store it in the meantime.
I don't find eBay to be a great way to sell items anymore, unless you have unique, collectible type things. Too many businesses use it, & people are more comfortable with Amazon when they want to order regular items from the internet. Also, difficult for furniture I think - too many people have turned to Craigslist for pick-up only items.
Craigslist has also gotten difficult, especially as a buyer. Too many people waiting to swoop in & pick something up immediately, too many sellers not willing to hold an item to the first responder so they can get there after a work-day. For sellers, it can be frustrating also - unless you have a really "hot" item (desirable, good condition, bargain price), people may respond just to tire-kick, or may not respond because they assume it's already gone & you forgot to delete the post.
I've had some good luck in the Facebook sale groups. There are many for various areas - do a search for "chicago sales" & I'm sure you'll find a ton. Some are better run than others, but I find there is usually an understanding that first to respond has first dibs, then when they pass, next in line is up. That is the format I followed when I sold some items recently, & it worked well. If I had a large number of responses, I'd let people know they needed to commit 1 hour after contacting me, & have pick-up arranged within the day (allowing some extra time if they needed to arrange a truck - in which case they made a cash deposit that day). The nice thing about these groups is that people can see who else responded - sometimes knowing there is interest sparks more interest, & it's not uncommon to sell items to the 3rd or 4th person. Be firm on your price, or know how much you'd be willing to bargain down for, which means setting a fair price to begin with. Be firm on your location for pick-up - do they need to come to you? Or will you meet in a public place? Are you willing to travel part-way to accommodate their schedule, & if so how far is reasonable for you? Don't bend over backwards to sell a $5-10 item, you know? (FYI - I've had easy sales where they ask where I'm located & come right over, other easy sales where they say they live somewhere else & I can meet them while out running errands, & ridiculous people who want me to be available outside of my area, during the workday, on a specific day only, so they can buy a $20 set of knives from me for $5... no thanks.)
So, long-winded... but hopefully helpful for anyone reading. T. :)