Excellent advice! Questing is far more efficient for leveling than grinding, although there are some legitimate times to grind. Like if you are shy of a level after handing in all your completed quests and being one level higher would mean you could train up. My general rule of thumb is if the mob is green or lower for xp and you don't need it for a quest objective, don't kill it unless you need to (like to get by to get to something you do need). Concentrate on yellow xp mobs or higher if you must grind.
Another good tip to add to your already superb one is to try to coordinate trips to town with visiting your class trainer. So, if you are toddling around Westfall at level 13 and you've picked up a quest to go to SW to drop something off try to wait until you hit level 14 before you go do that quest. It means one flight (so less money spent). When you are in town, make sure you do any banking, AHing, skill/weapon training or purchasing of reagents you need to do as well, so that you don't have to come back again for two levels when you need to train again.
If you're not very experienced or have a very bad memory or organisational skills then I highly recommend you download some sort of quest helper add on. These will do a lot of the 'where should I go, what should I do' work for you.
When you go to hand in multiple quests you have completed, always try to hand in the quests in order of higest difficulty first, i.e., red, then orange, then yellow, then green. If you hand in a load of green quests and level, the yellow ones may go green and you will receive less xp for them.