Clearance sections are specifically designed to trigger impulse buying through steep discounts - the challenge isn't finding a good deal, it's avoiding buying things purely because the price feels too good to pass up.
Browsing clearance with a genuine need already identified - rather than browsing purely to see what's discounted - filters out most of the impulse-driven purchases that end up unused.
A useful test: would you want this item at all if it weren't discounted? If the honest answer is no, the deep discount alone isn't a good enough reason to buy it.
Clearance items are frequently final sale, which changes the risk calculation - worth confirming the return policy before buying something you're not fully certain about, since there may be no way to reverse the purchase.