To maximize your XP gain, try and get as many IMPORTANT mind-Reads done as early as possible, and get some quests. Then, kill off as many enemies as you can. Finally, complete the quests - this doens't change the XP rewqard, but it does give you higher quality items as a reward. To sum up:
To maximize your XP gain:
1) Get some quests.
2) Mind-read anyone who is worth it.
3) Kill as many enemies as you can.
4) Complete/Turn in your quests.
