I've had a share in tickets for 20 years... And even in the bad years I've done okay.
I have no trade secret, and surely there are more resale tools today then there were 20 years ago, but if you are in it to survive (not make a killing profit), then I recommend:
1. Build a list of regular buyers who will commit to take a couple of games off you in the fall, before the season starts.
2. Commit to half a season on your own / with your buddy. We'll take 1/3 together, I'll take 1/6 for myself to use, as will he, and we'll sell the rest.
3. Commit to what you want early (in the summer, when the schedule is released.) I work two blocks from the Garden; my buddy works downtown. So its safe to say that unless there is a special occasion, we sell all the weekend games outright. If I already know I'll be skiing the Wasatch in January, I know that those games are on the block. I usually end up with 2-3 games per month, and try not to see any team twice if I can avoid it.
4. Get the liability off the books as soon as possible. Sell early if someone is willing to commit. I personally give up the opportunity to make a killing on a one-off game (Van@NYR, i.e.) in order to recoup my investment, which began back in May. As a STH, you already get a discount over the rack-rate, so use that to your advantage. Using the Hub or TE to resell gives back your advantage, so unless you have no other choice, word of mouth is your best way to avoid the vig.
Good luck!
-Doug