The Commendations you can get once you are Revered make Alts grinding the reps stupidly easy (plus they work for your WHOLE account, buy them on your Hordie on Trollbane and you get the bonus on your Alliance characters on Zul'Jin). Just from doing the normal questing while leveling in Townlong, my Alt is like 8-9k into Honored with Shadow Pan already without even touching a daily.
The only one that, I believe, doesn't carry overfactions (obviously) is the Operation: Shieldwall to Dominance Offensive reputation.
The Commendations pretty much solved the Alt rep grind issue as far as I'm concerned.
My Main is usually capped by Wednesday or Thursday. I run all the LFR's and Sha. I hit MSV with the guild and the couple of Bosses we have killed in HoF. After that, I hit a quick Scenario and a quick LFD. That get's you very close to being capped. Then I'll just do the dailies that I feel like working on.How in the seven hells can you stand to cap valor on 8+ characters? I can't even cap 2 of them....
After that, the VP flows in quickly for Alt's due to the bonus you get once a character is capped.