I am consistently running close to empty on soul gems needed to recharge my enchanted one hand, two hand weapons and Mage staffs. they are way too expensive to purchase so I'm wondering if anyone knows a good place or way to stack up on them so I don't have to be extra conservative with my best weapons. thanks all!

Go to the College of Winterhold.

Talk to everyone. You'll see.

in almost every dungeon i have been i have found several, from petty to greater, both filled and empty... thank goodness you can recharge weapons with empty soul-gems too

Dwemer ruins, most of centurions have soul gems.

If you have empty soul gems, you can cast soul trap spell on your enemy before killing them, then the soul gem will be filled with the soul of your enemy.
This way you don't have to purchase the gems.

For a couple of Enchanting perks (if you can spare them) you can get a perk that adds more charge per gem, and another that gives back charge after every kill.

Find the Shrine of Azura.

really helpful thanks guys, I'm going to purchase soul trap (yay)

this ^^

dwemer ruins keep me fully stocked. i haven't had to use a soul trap weapon/spell yet. for the larger gems though i find you need to find necro's for those.

'easiest' way it to make a soul trapping weapon. Unless youre a caster I guess. Soul trap spell is aimed and it can miss if you arent paying attention. I just make a grand gemmed weapon and go from there, I bought all petty and lesser regardless and then the empty for everything else. but i have a ton left over now and am already at 100 enchanting. So now basically all I wantis grand sized ones and I can buy them at this point. I would hope eventually we will be able to upgrade the lower ones into higher ones. As in 5 petty to make a lesser, 5 lesser to make a common and so on.

everytime I use soul trap it says " gem not large enough "...I literally have every sized gem empty by the dozen. why is this spell not working against normal foes like bandits and silver hands?

do the dwemer ruins respawn enemies?

you need http://www.uesp.net/wiki/Skyrim:Soul_Gem to capture humanoid souls. they are harder to find but look at the link and consider getting the black azura's star

Edit. ninjaed

You need Black soul gems, or Azura black star for humans,elfs, argonians and khajit.

For the pure, evil, merciless mini-maxer, the black star is a mandatory pick. I also buy all the empty soul gems I can lay my grubby hands on, for white souls, and my weapon is enchanted with a LOT of charges of 1 second soul trap. (I also dual-wield a 1 point fire damage enchant on the offhand, given that lighting enemies on fire increases the damage they take, according to the tips).

The result is my large stockpile of soul gems is routinely getting filled, which I then use to practice enchanting on my smithed products, and sell at a good markup.

gotcha ok thanks

Pro-tip

If using a companion, give them a soul trap weapon, and all of your soul gems (except greater, as they tend to fill these with 'common' souls)...

They will have you overflowing with soul gems in no time.

on the flip side and the reason i tend not to do this is that all my grand soul gems tend to get filled with petty or common souls just from encounters while running down the road (wolves and bears and such). waste of a grand gem right there.

A great tip, if you fill a soul gem and then drop it on the ground, when you pick it back up, it will be empty.

I use this when I fill grand and black soul gems with lower level souls.

very cool. thanks for the tip.