Few tips that worked for me. (Farmed TLPD 2x)
TLPD: shares the same spawn timer as Vyragosa. If Vyragosa is up, TLPD won't spawn.
A guildy found Vyragosa dead and stated in guild chat. I went back 7hrs later and I found TLPD's corpse. I checked back again 7hrs later and found Vyragosa.
The next 7 hours I found nothing. I checked back another 7hrs later and I found TLPD flying @ the end of my flight path.
The awesome part is that TLPD was my first flying mount besides my DK mount

Aeonaxx: also shares a spawn timer but with the Rare spawn bat. The bat doesn't stay up long before despawning. Once you find him, you have your spawn time. If you find him and it states that you can't mount/attack him, /reload UI. Don't rage quit. You are actually already on him. It glitches. (Also farmed 2x, lost 1 to phasing)
Rare Camel Figurine: Find it asap after a restart. Once you've found it, you can check back every 6 hrs and it's usually up. (Farmed 3x for friends/myself)
(Sadly it took me 32 figurines before I got the mount/title.)
Voidtalon: best to farm right after a reset. Within the first hour, realm hop one area until you find a portal. (Farmed this my 1st reset attempt -->
http://us.battle.net/wow/en/forum/topic/17083948505?page=2Poundfist: is just poundfist, 2nd group to farm it in US. But everyone has it now and coalfist is easier to get and looks cooler.. So yea..
Poseidus: Best to realm hop Thursdays-Saturdays in one location. (If no other restarts happen) (Farmed 3x)
The only mounts I afk camped 100% were Aeonaxx/Poundfist. The rest I either planned out or found while gathering herbs.
Hope this might help, goodluck friend /cheers