Easy way to get unlimited free arrows when your starting out. Find some guards target practicing and grab their arrows out of the target after they shoot them I grabbed about 50 in just a few minutes I found in solitude there are two guards target shooting and the arrows rack up fairly quickly

Also at the thieves guild training room

1) Give a companion a single copy of your best arrows and a bow. Only the player uses ammo, so they only need a single arrow.
2) ????
3) Retrieve magically created copies of your best arrows from corpses.


I've gotten over 50 glass arrows from Sven so far.