The refrigerator is certainly the hardest working appliance in any kitchen. (No offense, Mr. Oven!) For those who don’t cook, it’s busy holding your leftover takeout and bottles of wine; for those who do, it’s a constantly rotating repository for a mini grocery-store’s worth of goods. No matter how you use it, regular maintenance — plus a couple just-for-looks tricks — can help you love your fridge more and more, every day. Here’s what to do.