While I wouldn’t consider myself a “hardcore trader”, I certainly do it. Most TF2 players enjoy making at least one of the classes look as cool as they can afford, or grabbing strange versions of weapons they truly enjoy.
This pretty much requires using a significant amount of TF2 Outpost, which can be a great experience if you find a good trader. Unfortunately, the percentage of users who seem interested in making things fast, easy, and simple are vanishing every day. As a frequent buyer, my usual strategy is to search for something, open a bunch of tabs of online people offering a certain item, and then instantly close anyone who breaks the following rules:
(Note: These tips are for items that are in huge supply, like most strange weapons, regular hats, paints, etc. Very specific things like low craft numbers, unusuals, aren’t what I’m talking about. This is for when I want *something*, want to grab it quickly at market price, and move on with my life.)
1. Let them add you for a quick trade. The reason I only search through people who are online is because I want to do this fast. In real time. Before I go to sleep tonight I want this trade to be over. So when I see the words “Please do not add” or “Post here before you add” I’m already closing your tab. Because that means if I followed your instruction, I’d have to wait for you to see this trade, and then approve me, and then add me, and I might be offline by then…when there are dozens of other users online right now who don’t require this song and dance.
2. Put an actual price for everything. Again, I want this to go fast. I don’t want to post an offer in your trade, I want to know immediately what you want. If I like it, I’ll give it. Everybody knows the following item is worth 1.33 refined, dozens of users are selling it for that, backpack.tf lists it as the lowest price, I’m just going to do my business with somebody who knows this like I do.
3. Don’t sell items only as a set. Oh my god. There is nothing on Outpost that makes me close you sooner.
I input that I’m looking for a strange Bonk. That is what I want. I don’t want a complete scout set with an unusual, Gold Botkiller Scattergun and a Genuine Three-Rune Blade. If you won’t sell just the strange Bonk, I’m moving on. (I almost suspect these traders know this and are merely taking the opportunity to show off their swank loadouts, because this point seems really really obvious.)
4. Sell at what is currently the lowest price the item is going for. I’m not stupid. When I’m scrolling through my tabs, seeing the offered prices (“1.66 ref, 1.66 ref, 1.88 ref, 1.44 ref, 1.66 ref, 1.44 ref…”) I’m closing anybody not offering at what the lowest price is. All of your purple paints are exactly the same, no reason to pay more for them. This could be chalked up to common rates decreasing since you uploaded your trade, but in that case, keep your prices updated then! Even better, sell 1 scrap below the lowest market value. I do that whenever I feel like selling something, and I never have to wait for a buyer. It’s better than never selling it at all, or selling it in a week when the price has dropped further.
The thing you have to realize is, outside of unusuals and special circumstances, it’s a buyers’ market. The supply of run-of-the-mill stuff is overwhelming, and far more people are offering it than there are people looking to buy it. Some simple common courtesies go a long way towards getting more successful trades.