Too many times on forums sellers reveal too much weakness. Thread titles like : "Going out of business", "Leaving the domain business", " Need money desperately", "Get them before I drop them", etc...
There is no need to share that information if it is true, and makes you look foolish if you do not leave the domain business or drop the domains for sale.
The other thing about domains as opposed to say sports memorabilia, is that you have to keep renewing. If you try to sell a baseball signed by Willie Mays and you don't sell it, you still own it without any further expenditure. Domains are different in that someone can just look up the whois and see the expiry date. If you really are dropping it then they can pick the name up when it drops. Why pay $25 plus renewal when you can just pick the name up for reg fee.
Selling to other domainers is trickier in some ways because they know the game and the inventory that is out there on forums. You are not trying to sell for a fortune but you are trying to move inventory that will help you trade up to better domains or to pay renewal fees for your better domains.
Try to keep up on your domain portfolio management, accurately assess what you want to keep, what you will only sell for end user pricing and what is for sale at wholesale in the domainer to domainer market. The domains that you have picked for wholesale flipping should have six months registration left in my opinion. When you try to dump with just one month left that is where other domainers for the most part tend to just wait you out. Of course some domains sell in the last month, but the point is that you will do better over the long run by sticking to a more focused and meticulous system.
So make sure you don't seem desperate when selling, it just doesn't work on most domainers and they will just wait to pick it up on the drop. I have even seen a few times where someone paid $69 on Name Jet when the previous owner offered it for $25.
Please feel free to leave a comment and discuss your success or frustration selling on domain forums.