I used to save things to sell online. I was going to start an account on eBay, and Craigslist, and anywhere else to push my items and make some money. The problem is that I am not a saleswoman. I never have been. I was saving things in hopes to make a life change, possibly even a character change - to really love selling things online.
The idea is smart: take your used item, post a pretty picture of it online, and let the buyers come to you. The problem is that in all actuality, unless you are super motivated to meet someone in a public place to discuss your $6 lawn chair (and they will barter), you may end up never finding the drive to sell online. It is a lot of work! The back and forth emails with the buyer, the where to meet, the "is this just a scam?" . . . all of these things take effort on your part as the seller. But . . . do you have what it takes?
Consider hosting or participating in a group garage sale - a neighborhood sale. A way to take one day, hawk your most prized possessions, and have friends or neighbors there for support. The power of a garage sale is this: you may struggle on garage sale day with "should I sell this? I LOVE this and cannot part with this!" When you finally put your items out for display, and place your (most often overpriced) price tag on the item, you may watch people walk right past them. This will help you see the item at face value.
Rethink sentimental value - and then, let go of all of the knick knacks that clutter your house, and your life. There is no reason to have knick knacks stockpiled away in drawers and boxes.
AFTER A GARAGE SALE:
I learned from my mom the idea of the Craigslist "curb alert" . . . a way to have people pick up items from your curb that you no longer need. I took a picture of all of our prized possessions that no one wanted after our garage sale, and posted it on Craigslist under the FREE section. Within 10 minutes people were there, picking things up. I helped people load up toys, a mattress, book shelves, and all of my kitchen ware that I had no use for. It was uplifting to see people walk away with a smile and free items :)
More importantly, I had successfully gotten rid of all of the things that were weighing me down!