There are no secret tips or magic potions to get decent seats, just some things we've figured out by using presale codes or  making regular onsale ticket purchases for awhile now.
Here is a list of ideas:
Register credit card at ticketmaster beforehand. In case pull good seats, you wouldn't want to lose them if get timed out.
Be early at ticketing window. And don't leave if the presale window doesn't open at the said time - there have been delays up to an hour and those that stay get less competition as many said 'the heck with this'
Do some fishing of tickets. Sometimes the first pull is nosebleeds, while 10 minutes later you find row1. Go figure. For extremely hot ( read that as Hannah Montana, Bon Jovi ) - we wouldn't fish too much
Get an Amex card or find someone who does. The Amex only presale is for Amex cardholders - how narrow is that? compared to the all can get in AEG/ Radio/ Venue presale.
Watch for second shows. If the tour has any room, additional dates might be added should sellouts occur.
If resorting to re-sellers of tickets. Wait and wait - why rush? Prices will drop as near the show date and re-sellers want to unload tickets.

Probably skipped tons - but wrote this up in 10 minutes. Might come back to edit. Oh, and if you like please vote 'yes' as we like the little icon eBay gave us.
Have a nice day.