This is actually not about managing time in terms of managing play time, but about managing time within the game. When your WoW time is limited, you have to make decisions about what to spend time doing. There are literally thousands of things one could do in game: quests, dungeons, raids, achievements, gathering materials and crafting things from those materials. All those things take time but have certain rewards.
I now have 3 characters to play with. The one at the left is my main character, the one who's at the top of her game (though she can always use more gear). Her skills are maxed out. Many of her faction reps are maxed out. With the exception of one top-level raid, she can pretty much do whatever she wants. What I've been doing with her lately is simply running her through a few dailies. When a good dungeon run opportunity crops up and I have the time, I will run that as well, since the rewards are tokens for good gear. On any given day, I can spend less than an hour on her and she won't really suffer much if I don't play her at all.
My other max level character is Zamar, who I just moved from another server and who has such bad gear that what she can do is limited. She needs to run dungeons, but she's not geared enough for some of them. She needs faction rep to obtain gear and that requires quests (some daily, some long series of quests), which can be quite time consuming. And then I have another low-level character that obviously needs a lot of work. So, if I only have an hour or two to play, I have to prioritize what I do, especially with these lower level characters. This occurred to me the other day as I was standing in the middle of a city, trying to decide which direction to go. And then, I thought, hmm, this is a dilemma most people have in real life. How can this transfer?
When I log into WoW, sometimes of course, I'm just planning to goof around. I play as a respite from work. But sometimes, I have goals, just like I do in my work. I go through a series of questions as I try to determine what to do. And I think this series of decisions might be a good thought process for any decision. So, here it is:
1. What is most important for this character right now? What is he/she most lacking?
2. If the character is not lacking anything, what is a good reward for him/her right now?
3. What task will get the character closer to the need/reward?
4. How much time will that task take?
5. If the task time > allowed game time, what is the next priority or can a part of the task be completed in the allotted time? (Then jump to 4).
6. If the task time < allowed game time, go do task.
This is pretty much the same decision tree I use in real life. I often have a list of priorities and I simply decide which one gives me the most bang for my buck in the time I have at hand. The hardest decision is the first one, deciding what's most important. In the game, it doesn't much matter. In life, there can be some unpleasant consequences. For example, if I were to prioritize gameplay . . . .