Infusing liquor is not an exact science, but a matter of taste. Infuse each flavor to your own taste preferences and if it ends up too strong, you can dilute it with additional liquor.

Using extracts is the fastest way to make a batch of liqueur, and in some cases where this is the best way to get the flavor you're want. You will get the best results when you slowly infuse the liquor with fresh ingredients.  Using fresh ingredients also allows you to introduce more variety; you can't find as wide a variety of extracts and essences as you can of fruits, herbs and spices.

Here are some ideas:

Whole fruit should be sliced and/or mashed to allow the juices to escape and let the liquor come in contact with as much surface area as possible. Leave the skin on for maximum flavor. Fruit: Strawberries, cherries, peaches, tart apples, pineapple, pomegranate seeds, dried apricots, dried sour cherries, orange zest, lemon zest, raspberries, blackberries, blueberries, kumquats, or cranberries.  Just use your own imagination and taste buds!

Herbs and spices: Vanilla beans, peppercorns, hot chiles, coriander seeds, cinnamon sticks, cloves, nutmeg, dill, thyme, basil, lemon grass, tarragon, rosemary, garlic or whole coffee beans. 
go easy with the cloves and nutmeg: too much of these  can produce a numbing effect in your mouth!

Try combining a couple of different flavors: how about orange-cranberry, chile-lemongrass, lemon-tarragon, apple-cranberry, orange-pineapple raspberry-vanilla, pineapple-banana or apple-cinnamon? Just don't try to pack too many different things into one bottle, or you won't be able to tell the flavors apart.

Once you've chosen your alcohol and your flavorings, simply combine them.

• Put flavorings right into the liquor in  any glass jar or bottle with a tight-fitting lid.
• Keep the bottles in a dark place and leave it at room temperature. Or put the bottles in a paper grocery bag and stir or rotate them a couple of times per day.
• Depending on how potent your flavorings are, you'll need to let them steep for anywhere from a day to a few weeks. Most fruit needs a full two to four weeks for all the flavor to be transferred to the alcohol, whereas chiles, garlic, and most fresh spices only need a couple of days.

Smell and taste the infusions to decide when each is ready.

If you've used mashed fruit, your iliquor is now going to have bits of sediment in it. Simply line a strainer with a coffee filter and  pour the liquor through slowly. Don't try to save the fruit. 

To sweeten your liqueurs, don't add sugar directly to the alcohol--it will take too long to dissolve and you won't be able to tell right away how sweet it is. Instead, make a simple syrup of two parts sugar to one part water. Combine them in a saucepan and simmer them on the stove until the sugar is completely dissolved. Let the syrup cool to room temperature and then sweeten the infusion to taste. Once a liqueur has been sweetened, most of them taste better after they've had a chance to "age" for a month or so. Aging allows the flavors to mellow and blend.

Find interesting glass bottles (if they don't have tops, you can buy corks at craft stores or winemaking supply shops). Create your own custom labels and "garnish" each finished bottle by dropping in a small quantity of the original ingredients (a few berries, a twist of citrus zest, an herb sprig, etc).

Serve straight out of the freezer, mixed into a fresh cup of coffee, drizzled over a scoop of good vanilla ice cream, substituted in a traditional cocktail or have fun inventing your own brand new signature drinks!

• Creme De Cacao (Chocolate Flavored Liquor)