MONDAYS & TUESDAYS are the best days - lots of donations come in over the weekend and get put on the shelves those days.
TRAVEL OUTSIDE YOUR NORMAL AREA to discover new to you thrift stores.
LOCATION. I've found the best stuff in thrift stores in older neighborhoods.
AVOID THE "FANCY" HIGHLY CURATED GOODWILL STORES.
DRESS APPROPRIATELY - If buying clothing, wear form fitting clothing you can easily try outfits on on top of.
GET TO KNOW THE EMPLOYEES - they may be able to give you pointers on store sales coming up.
KEEP A BOTTLE OF HAND SANITIZER IN YOUR PURSE - for grimy purchases.