If you play on a limited schedule because of family, work, or business like I do...almost everything other than mechanics will apply. Why is that? Because I often must be able to simply drop whatever I'm doing in-game for something more pressing or important IRL.
Let's expand. As a healer, I understand that my role is to be there to facilitate a group as they work toward a goal. Traditionally, this means healing a heroic instance, a raid, or a PVP battleground or arena team. Since I've been forced to focus on PVE for so long, that is my passion. I do not always have time for a heroic, because I have set a boundary as a casual player. How so? I intentionally label WoW as my "HOBBY"...and much like other hobbies, I do not allow it to monopolize my time when I would rather be spending quality time with my wife, family, or friends. The in-game effects are: I have to be doing something that I can terminate immediately without letting people down. I don't want to be constantly leaving instances midstream or leaving guildies hanging. I had to once this week and I felt bad.
So, what do I do? I efficiently manage time on the AH with TSM. I used rested exp to finish leveling a new toon, Smoogehunt. Even as impressive, I maxed out jewelcrafting and inscription on that toon. (Those professions were my motivation for starting the character in the first place.) I efficiently complete daily quests on my DK and gather at the same time (currently in Deepholm for 1 more day to exalted, then probably Hyjal or Uldum).
I also gather quickly for very basic mats...right now, Uldum is a cash cow. With the max flying speed on a Tauren DK, I can pick up 4 or 5 stacks of Whiptail in 20 minutes, and that will also inevitably be enough Volatile Life for my daily transmute to Volatile Air.
I complete a daily jewelcrafting quest, and I have accumulated 5 profitable patterns already.
Bottom line? With a sporadic schedule, and only bursts of playable time at random times during the day, I purchased Staff of Dark Mending for the priest at 18,000 gold. Enchanting is maxed and I self-enchanted the new staff with Power Torrent (not cheap). I am now back up to around 12,000 gold, and that is after purchasing 6 heirloom items from the guild vendor (for the new leveling project Smoogebear).
I have not run as many heroic instances as I anticipated, but I correctly gemmed and reforged every single piece of gear for Disc, according to my research and guild suggestions. I have accumulated 3 new 345 item level pieces, and I plan to purchase a Sandstone Drake within a week or so. This is all with about 30 minutes played on average each day.
Three 85 characters, plenty of heirloom gear for my next toons, a priest that is gearing up nicely and a DK that can pull weight in heroics (thanks to the BOE maces from ZG that sell for 1200 gold now...Hercpilot has two of those and a good PVE DW frost spec).
I am really big on systems for success. In business, this is very important...true residual or passive income can only come from a successful system, not raw amounts of effort. And that applies so well to WoW as a gaming hobby! My system involves efficiency tools like TradeSkillMaster and Auctionator, a good UI that carries well for multiple classes, clear boundaries regarding playtime (so I don't have to feel guilty about playing), and the knowledge of how to get the biggest bang for every minute I'm logged on. I know there are higher levels of AH, raiding, or PVP success available...but I am very happy because I can still enjoy my favorite game without a 3 hour per day requirement.
As a caviat, I want to thank Krrang of Alchanon for welcoming me so warmly on a new server. If you haven't heard his podcast, you really should check out "Love to the Guild Leader" on iTunes. And congrats on level 25! I hear they just dinged about 12 hours ago. I plan to post some more on leveling tunes quickly and how that might apply to overseas/deployed/crappy-connection gameplay, so rest assured I am carrying on the specific strength of this blog.