Trading is fun and really rewarding. I've been trading online since I was about 15 years old, and I don't have any idea how many trades I've done. Into the 4 digits is possible, but probably around 700 to 800 is more accurate.
The first thing you need to do is figure out what you have. You can't know what you want until you know you don't already have it.
Figuring out what you have is easy. With over 1 million cards scanned onto this site, even if the card you have is not scanned yet, odds are another from the same set is, unless it's really out there oddball stuff, in which case, a post on the Card ID forum can solve that particular problem. Don't forget you can use the filters on the team or player page to match card numbers. It does work, I've done it.
I don't know how many cards you have, but it would probably be easiest to sort them into sets and go from there. Having to "hunt and peck" and keep going back to the same set gets very time consuming. When I joined on here I just went through my paper listings, and entered in the ones I had. If there was a question I did nothing until i found the card, but I didn't have any cards in hand for 99% of the collection. Not as many people are OCD about keeping track as I am though.
Next, enter in what you have. Decide if it's something you want to have or something you want to trade for something you'd rather have. (For me, I want everything, I only trade duplicates). If you don't have it, but wish you did, then you add it to your wantlist. I only enter sets onto my wantlist when they are too close to rationalize buying a box of, even though health related issues cause me to not be able to buy boxes very often.
After that, just wait for the trade offers to roll in. List everything you have to trade, even from common sets. I was surprised because the most common NASCAR set ever was the first one to go when I entered my tradelist. I figured everybody who wanted it already had it but I was wrong because multiple people wanted them. There are a lot of set collectors on this forum that may need just one or two common cards to finish off their set.
I personally only list flawless cards on my tradelist. I'm very strict with that. Any flaw and it goes into a reject box. That would be corner wear, surface scratches, etc. Those two are the most common. Don't throw them away though, somebody wants them. I finally found somebody who wants my rejects, and will be sending him a large box fairly soon. I will accept imperfect cards but I don't send them. Older cards are a little different, when I get 70s or older cards I don't expect them to have perfect corners and will list imperfect cards on the tradelist then, but it's rare when I get any spares.
Mainaining the tradelist is a chore. It's time consuming and not particularly easy to do. I have not really entered much new onto mine since 2014 or 2015. But the results are worth it. Through trades on the Database alone I've completed about 25 sets.
For shipping out cards, use a padded envelope, not a PWE. (plain white envelope) It costs more, yes, but nobody is going to trade with you if you get a reputation for having cards arrived damaged. Unless, of course, you agree to use PWEs beforehand. You can get padded envelopes/bubble mailers for pretty cheap, I think you can get about 6 of them for $2. Maybe more. I bought so many at Wal-Mart one time that I won't need to restock for a couple of years. You can also reuse them as long as you tape them up really well and totally cover the previous writing on there. (an index card works well for that, but a piece of looseleaf or typing paper also works)
Cards sent through the mail should be sent in a penny sleeve inside a toploader, preferably in a team bag. Don't use tape on any of those three things as it can damage the card, and that's the last thing you want.
Hope that helps, and good luck!
VERY slow trading due to health problems. Not transferrable so safe to trade with, just moving is painful and can't always access the cards.
Cardboard History My COMC
New Collection Website: Cardboard History Gallery (Still under construction)
Tips on how to make your scans look like the card does in hand (No more washed out, fuzzy scans!):
