Come holiday season, your oven is going to see heavy use. Whether it’s baking delectable cookies and pies, turning out beautiful breakfast bakes for Christmas morning, delivering the perfect side dishes, or roasting the holiday beast, your oven will be working nonstop—and you’ll depend on it to be in perfect working order. How can you be sure that it is?

Calibrate It

Of all preparations, it’s most important to make sure the temperature inside the oven matches the setting you’ve chosen. If you don’t have an oven thermometer, this is the perfect time to get one. Oven temperatures do fluctuate, so once the oven has preheated, check the thermometer repeatedly over a 10- to 15-minute period. Some ovens can vary up to 50 degrees from their set temperature, and that wide of a range can have a huge impact on cooking. Think about it—50 degrees too cool and you’ll have a hard time getting that lovely brown crust on your holiday rib roast. Fifty degrees too hot, and your most delicate cookies will go from underdone to singed in the blink of an eye.

Depending on the kind of oven you have, you may be able to calibrate it yourself; check the owner’s manual, either in print or online. If you can’t find either type of manual (and you don’t have time to call a specialist), just compensate with basic math—set the oven higher or lower by the number of degrees by which the temperature is off.

Level It

This step is super important if you’re a baker. Turkeys and roasts probably won’t be affected by a slight incline, but a cheesecake or a pumpkin pie certainly will, and you’ll get more professional results if your oven doesn’t introduce a natural tilt to the top of a cake. Grab a carpenter’s level (if you don’t have one in your household toolbox, you can pick one up at the hardware store for a few bucks) and lay it across the top of the oven—first across the width, then from front to back. If the oven isn’t level in either direction, pull it away from the wall and adjust the height. (Having a partner can be helpful here.) Most ovens have adjustable feet mounted on threaded screws; you can raise one or more corners of the appliance quickly and easily simply by twisting them. Check again with the level until you’re satisfied. Your baked goods will thank you.

Clean It

A shiny, clean oven will certainly impress visiting friends and family, but on the practical side, a dirty oven can interfere with cooking times. However tempting, don’t use the self-clean setting for a last-minute scrub. The self-cleaning cycle works by raising the oven temperature to anywhere from 800 degrees to over 1,000 degrees, burning the food residue inside to ash; it actually puts stress on the appliance, and is the most likely time for the oven to break down. Not what you want on the day before you’re due to serve the Christmas ham to a dozen guests! Plus, it’s always a good idea to open windows for the best possible ventilation when using the self-cleaning setting, and if you live in a cooler climate, that may not be an option around Christmastime. Instead, learn how to clean your over a different way.

A few simple steps—calibrate, level, clean—and your oven will be as ready for the holiday season as you are.