Smell does more for a Christmas mood than almost any decoration, and the best Christmas smells are cheap. Most of them come from the kitchen.

Three simmer pots

Put everything in a saucepan, cover with water and keep it on the lowest heat so it steams without boiling. Check the water every 45 minutes or so and top it up. Turn it off when you go out or go to bed. You can keep the same pot going for two or three days: refrigerate it overnight and add fresh water in the morning. In an apartment, half of each recipe is plenty.

Citrus and spice. 2 sliced oranges, 3 cinnamon sticks (on Amazon), 1 tablespoon whole cloves, a couple of rosemary sprigs and 1 teaspoon vanilla. The classic, and under $5.

Pine. A handful of fresh pine, fir or cedar clippings (tree lots usually give their trimmings away), 1 sliced lemon and a few drops of peppermint extract. Good if your tree is artificial and you miss the smell. Pine-scented cleaner is not a substitute.

Apple. 2 sliced apples, cinnamon sticks, a few whole allspice, 2 star anise and a drizzle of maple syrup. It smells like a pie is in the oven. Don’t add more than two star anise; any more and it smells like cough medicine.

Candles

One good candle in each room you’re actually using, lit for about an hour before people come over, is enough. Lots of different scents at once just smells like a candle shop. Pick one family for the whole place, all warm spice or all evergreen, and stick to it.

Trim the wick (on Amazon) to a quarter inch before you light it, since long wicks leave soot on the walls. Stop burning when there’s about half an inch of wax left, and keep candles well away from garland, curtains and the tree. Flickering battery candles are a good alternative anywhere you won’t be sitting and watching.

A homemade reed diffuser

A small bottle, some carrier oil, around 20 drops of essential oil (pine, cinnamon, clove, orange) and a few rattan reeds (on Amazon). It costs about $4 and lasts for weeks without a flame or a plug. Put it somewhere the air moves, like near a doorway, and flip the reeds once a week.

Using the oven

After baking. When something comes out of the oven, put a tray of orange peels, cinnamon sticks and cloves in and leave the door open a crack while it cools. The leftover heat does the work. Keep citrus peels in a bag in the fridge during the week for this.

A tray of spices. No baking planned? Cinnamon sticks, star anise, cloves and dried orange slices on a sheet pan at 200°F for 20 minutes. A toaster oven works too. The spices can go back in the jar afterward.

If you have pets

This matters more than anything above. Many essential oils are harmful to cats and dogs: tea tree, pennyroyal, wintergreen and pine oil are the main ones for cats, and cinnamon and clove oils can irritate both. Simmer pots with whole spices and fruit are generally lower in concentration, but leave out any essential oil drops when animals are around. Keep simmer pots and candles where a cat can’t reach, and diffusers up high. Sneezing, watery eyes or pawing at the face mean the smell is too strong for the room.