Go to Periyte's shrine, the one with the circle of "unconscious" people, and use a weapon to hit them and get them all by the rocks.
Then have a lot of cheap weapons (for whatever skill you want to get up) and some repair hammers. Get near one of the people and start hacking/slashing/blasting/punching/shooting away.
you can change the channel and watch something else. Check back every once in a while and repair your weapons or whatever.
After your skills go up fast travel/ride to an inn/house (there is an inn along the river to the west of the shrine) and sleep and level up (sometimes you can gain like 3 levels, to check either sleep again after you level up or just look for the level up symbol to the right of your compass while playing).
This is a great way to gain levels because the people will never die and you can't get in trouble.
Warning: if you do the actual quest for the shrine the people will be alive and will die if you attack them!