Why not buy them yourself? I have a hard time buying nice clothes without some female input, but jeans I can manage.
I can get rugged, thick denim jeans brand new in the exact size I need from Costco for $13. Thin, half-used jeans in the thrift store are $5-$10. Not really seeing a value there, as the lifespan will be dramatically less.
Other stuff I typically get at 80+% off at department stores brand new, often stacking a coupon on top of that (ie $10 off $30 or whatever). I recently threw away some receipts where I had purchased over $300-$500 (retail suggested) in clothes at 95+% off from department stores. So, $400 list price, paying less than $20. Used to be able to do some really brutal stuff in JC Penney on the right weekends - that went away 2 reorgs ago.
Current target is Kohl's: I will get a $10 "Spend on anything" coupon in the mail, then stack with a $10 off $30 coupon and select items from sale or clearance. For good selection/specific need for the toddler, I'll get 6 of the ($12 on sale for $5) items to total $30. Then use $10 off $30 from my coupon app to get down to $20. Then use the $10 "use on anything" coupon to get down to $10. That's $72 "list price" for $10, or roughly 86% off. $1.67 per brand new toddler item (pants, shirts.)
However, if you don't mind the thinner selection, hit the 80% off racks to get up to your $30. Then use the $10 off $30, then use the $10 off anything.
Kohl's is walking distance from my work ;)
Frankly, thrift stores are often not a good enough value for me. But then again, the thrift stores (and semiannual kids consignment events) are pretty crummy/expensive around here.