I depend a lot on hand me downs- but buy from Old Navy for t-shirts, Kohl's for higher quality, and Sears and JC Penney's for good quality and modest jr. depts- bought two swimsuits at Sears last week at the Land's End area, I didn't realize they had that!
This year we'll be buying uniforms from a uniform store and black dress shoes at Sears, My favorite thrift store has a uniform section where I can find some navy and white sweaters, etc.
I think it's hard to keep everything rotated and seasonal, I seem to be running out of energy to do this sometimes. It's more time-consuming than you would think- I know dh never gives it a thought! I try to keep 4-5 outfits per kid rotating, they get pretty heavy wear, but last well-some of the hand-me-downs wear out, but we have lots coming in!
On the other hand, shopping with the kids last week was very fun- we've been frugal a long time, and the kids enjoyed buying a few things, and it was essentially cash. We also went to the crepe store and split a few crepes- Nutella, strawberry and veg Santa Fe-delicious!