I'm going nuts on the enchanting thing and am constantly running out of filled soul gems. So I have to end up running around looking for bears and trolls yet inevitably end up with the lesser souls of wolves. I don't care too much to go through the trouble of killing mammoths to get grand souls. Common and Greater are fine. Although enchanting things with grands bring bigtime $.

Petty soul gems are easy. In the real world mudcrabs would have been extinct by my hand at this point but they're always plentiful and will walk up to me and offer up their life energy in exchange for a firebolt blast to the face.

In a thread I was reading yesterday they mentioned draugr death lords for lvl 40's or so for grad souls, other than mammoths and giants. Greater I'd assume maybe the higher up draugrs like restless or above maybe? Dungeons are a sure place to go.

If you have azuras star and didn't take it to the shrine you can use it to trap human souls(bandits are plentiful in skyrim) and then you have a 100% chance at grand souls.

Soultrap Falmer go to Blackreach or Druegur.

If you have access to a staff that summons things, the Summons can be used as Soul Gem fodder.
The Atronach Forge under the College of Winterhold can be used to make staffs that summon Atronachs.

<sub>You can soul trap Draugr and Falmer? I did not know that. I thought they were soulless undead, just like skeletons. If that's the case then my worries are over. There's a bunch of places where those guys have either respawned or that I can just quests for. That makes life much easier.

Thanks!</sub>

Do the Break of Dawn quest at Meridia's Shrine, which is a little west of Solitude. You can collect a bunch of grand souls by killing the Corrupted Shades inside.

Yeah, I asked about Grand Souls in a thread yesterday and do what Gator Country said. I got 19 Grand Souls from those Shadows. Also, I got Grand Souls from the Falmer Shadowlurkers and Shadowmasters, plus you can actually mine "Geode" veins in Blackreach and some produce soul gems (empty); I got all ranges from Lesser to Black.

Also, I've given up trying to recharge my weapons, but I wouldn't ever use Grand/Black Soul Gems to recharge - not that you are.

Edit: people were unsure about Draugr Death Overlords - someone said that only the ones with Ebony Bows/Arrows yield Grand souls.

Draugr tombs for generic soul stones. If you have lots of black, then any old bandit hide out will do.

Glad to help.