Well it's not something that you should be hunting, because you got a long time until anyone would trust you with funds. However here are few tips for you:
1. Do not ask how to become an escrow.
2. Do not farm posts or merit.
3. Be polite as well as contribute to the forum.
And finally, ask yourself why do you want to become an escrow? There are already alot of escrow's on this forum, and it does not really pay that well for most.
From here you can find the updated escrow list:
https://bitcointalk.org/index.php?topic=2439910.0