I received a fabulous tip from Jayhawk recently on where to access the trading post.
"I've found one's home WvW
Borderland to be the best place to trade/craft. The TP is very near a
waypoint and it's close to the crafting stations/bank as well. Usually,
you'll also have access to the Mystic Forge in the garrison and when you
log back in, you're still wherever you left from making it easy to sit
next to karma merchants or farming nodes you want to readily have access
I'd like to add to these tips with the following suggestions:
1. Get the largest bags possible for your trader. This will cut down on the number of times you need to load items off the trading post and to/from your bank. I recommend the 20 slot gossamer bags.
2. Have movement speed talents and runes. As an elementalist, I use double daggers, Signet of Air, Conjure Firey Greatsword, Zephyr's Speed, Lightning Flash and "of the Traveler" runes.