I have found an interesting loophole (or Bug if you like) involving fast travel in the game Daggerfall. There are two methods for fast travel : reckless and cautious. If you choose reckless, it will take less time, but when you arrive at the destination, your health points, fatigue and magicka will be the same as what you have when you left. If cautious is chosen, it may take twice as long to travel, and you always have your health, fatigue and magicka fully charged. Also, if you are not a vampire, you will always arrive during day time. The loophole here is that if you are inside a town, you CAN fast travel to the town you are already in! By choosing cautious, and fast travel to the town you are in right now, you can fully recharge yourself of health, fatigue and magicka. If you fast travel during the daytime, the game clock will advance about one minute; if it is night time, you will arrive the next morning. So, you can have practically unlimited magicka during the daytime outdoors. There is only two drawbacks. First, you always arrive at the edge of the town. So if the town is huge, like the daggerfall city, you need to run around town again. Second, you can not fast travel when there are enemies nearby. However, you can always run to the other end of the town, lose the enemy, and then fast travel to recharge yourself.
This is ideal for training your magic skill. I have seen certain hints saying about custom practice spells. After you used up all spell points to practice the six schools of magic, you rest in a tavern to recharge the magicka. You don't have to! Just make sure it is still day time, fast travel to the same town you are in, choose cautious, and you will arrive fully recharged, ready to practice magic again. If you have a couple of quest pending, and can not waste time staying in tavern, this is the trick. After discovered this trick, I rarely use the inn or the fighter Guild for resting.