Open the bottle of gin. Pour out about 1/4 cup to 1/3 cup gin (reserving for later use). Add in juniper berries, allspice berries, orange peel cloves, and cinnamon.
Put lid back on the bottle. Let infuse in a cool, dark place for 12 to 24 hours, checking along the way until the flavor is how you like it.
Strain the infused gin through a fine sieve into a jug or bowl. Clean the bottle you infused the gin in. Add the infused gin back to the clean bottle.
Store in a cool, dark place for several months. Enjoy as desired!