Consider using flashbacks. These are formed when you take out a few events from a sequence of events and place it somewhere else to create a flashback or to account for such “time slips”.
What weaknesses, problem behaviors/attitudes or less-than-stellar aspects does each character have? Choose things in need of resolving, or that can be made much of, even if unresolved. Include at least one character who is somewhat lost/confused/befuddled and is a bit of a seeker. Seekers tend to go on quests, to fix internal issues as much as solving external problems. Avoid the Mary Sues, those “totally perfect” people. If you think that you know such people in real life, remind yourself to take off your rose-colored glasses.
If you send out someone on his, her or its own, don’t make this person or creature perfect from the get-go. Your story will fizzle quickly. It may well be that this person is viewed as courageous, amazing or incredible by the local townsfolk or whomever, but that’s all the more reason to show this person or creature has many weaknesses and bring them to the light throughout the journey. If a pair goes, be creative about their reasons for being together. Love is not enough; if that is used as the initial motivator, you will need to find the flaws in that love and test it to its absolute extreme to keep things interesting. Possible pairings could include: siblings, parent and child, neighbors, two diametrically opposed individuals, master and apprentice, leader and foot soldier, rich and poor, and so forth. If you make them equals, there needs to be something uniquely fascinating about their individual characters to keep them interesting.
Intersperse the conflicts with some quieter times. During these times, don’t cause a lull of boredom; instead, use these to explore the feelings, thoughts and desires of the characters and to fill the reader in on much-needed news about how the bigger picture story is progressing (such as whether Kingdom X has almost expired due to the quest object not being back there yet, or the way ahead becoming more treacherous than anyone in the traveling party has yet comprehended, and so so forth).
