Alright guys. You just made it to your home city, and learned Teleport: Illium / Thayd / House / Transmat.
Or maybe your Path ability, like Vendbot, Recall, or whatever.
This exploit is very simple.
Press N to open your queue for whatever tab.
Queue into a practice arena match. You don't need a party/group.
Accept the queue and enter the arena.
Once inside the arena, tell your random partner to **** off, the type /leave
NOTE: Only typing /leave is necessary.
You will exit the arena, back to wherever you were when you queued.
But wait, your cooldowns are all refreshed.
That 24 hour Illium teleport cooldown is refreshed.
I found this out because I didn't know how to get back to Illium from the grimvault mass transit. lol.
tl;dr
To refresh all of your spell cooldowns, queue, join, and leave a practice arena match.