My main suggestion is don't fast travel a lot. The best part of this game is the world it is played in. The terrain is beautiful and many of three most interesting and entertaining things I've seen are just random [censored] I've come across running through the wilderness and you miss all of this fast traveling everywhere.
This is good advice. Also, while your walking, it helps to add the points that pop up on your top bar to your map. Even if you don't fast travel later, you will know where you're going. You might even get to kill a few snotty bandit gaurds that are lollygagging outside, and pick up their loot, so double bonus.
That being said, try not to venture into too many places unless a quest sends you there. It does limit what you can find (Balors Oath Blade for example, in a cave, and you will never be sent there on a quest), but I have found myself running back through an entire dungeon to find a book that i could have picked up the first time I was there. I also find myself with weapons or books that i can't drop because they are plot items, but I have no idea who the items are for (Hjalti's sword for example...).