Learn the sale rotation of you thrift stores.   Unless the item is priced very cheaply, you might want to wait for the sale day to buy it. 

 Remember to be there at opening on the sale day.  Shop the department first where you need the most stuff. 

Leave your children home on sale day.  They will not be as thrilled as you are about shopping.

Ask about the return policy.  Some stores will allow returns so you can try things on at home.