1. How many more weeks can I wear this item? I know that it can be difficult to pass by a cashmere turtleneck that is marked down to $20, but is that something you are really going to reach for when the weather warms up? If you live in the Midwest, you probably have at least two more months of wearing winter clothes, but my Southern readers should be wary of buying clothes that won't be able to be worn until next winter. Although there are some basics that you should always have around, I don't suggest buying an entire season's wardrobe many months ahead. Styles change, new items come out that you like better, and your size can fluctuate. Save your clothing budget to get some fun spring pieces that you can enjoy in the nearer future.
2. Can this transition into spring? Long sleeve shirts are great to stock up on because they can be worn now with sweaters and also on their own for spring. Patterned scarves and brightly colored belts are also perfect to pick up on sale because they are mostly season-less.
3. Would I have liked it enough to pick it off the rack when it was full price? This is different than being willing to pay the full price. Too often people buy sale items because it fits and is a good price, but they don't actually have any positive feelings about the item. If you feel ambivalent about an item, don't buy it! You might have to go into multiple stores to find what you are looking for, but shopping the sale rack does not mean having to settle for the leftovers.
Good luck with your shopping and be sure to let me know in the comments if you find anything especially wonderful on sale!