I suggest regularly switching your mini-map between herbalism and mining. Veins and herbs sometimes occur in unexpected locations and behind other items that block your view. You're likely walking past many veins if you just have herbalism running on the mini-map. You'll find veins and herbs in 'awkward' spots, like near bunches of mobs. I think its Blizz way of making you 'pay' for them by needing to fight those mobs first.
If you're Alliance, tin veins first shows up in Westfall in and around the Gold Coast Quarry.
Edited, Aug 10th 2007 10:08am by ItsaGaAs
Edited, Aug 10th 2007 10:10am by ItsaGaAs