Theres a lot of money to be made in coffee. Especially if you offer breakfast or European style food, you should invest in an espresso machine. Here are some classic coffee drinks to get you started with a great menu your guests will love:
Espresso - the classic. Just, you know, turn on the espresso machine, pack it up, and voila! There are still several things to consider however. Beans are ever so important - and especially with espresso, if you cut corners on quality, your guests will be able to taste it. Size is also something to take into consideration. For a coffee shop, consider a larger size, whereas an after dinner espresso may be better small. Consider offering decaf espresso as well for diners who don't want a huge caffeine boost in the evening, but do appreciate the palate cleansing cadence a good coffee drink provides after a good meal.
Espresso Roma - see above, but add a little lemon twist as a garnish. This classic Italian beverage is a light, refreshing finish to a good meal.
Cafe Bombon - less well known and delicious, this popular Spanish coffee drink combines espresso and condensed milk in a 1:1 ratio that is simple, sweet, and delicious. Serve over ice for a sweet dessert treat.
Affogatto - another Italian classic, gelato is served with an espresso on the side, and then the two are combined table side. The hot espresso will melt the cold gelato and make a sweet, cold, creamy treat which is perfect for the hot summer months.
Cappuccino - another one of the classics. 1 part espresso, one part steamed milk, one part foam. If your barista is trained classically, they can make cool latte art on your cappuccino which will impress your guest and provide a pleasant visual to your presentation.
Latte- the cappuccino's simpler cousin - just add 1 part espresso to two parts steamed milk. Consider offering different types of milk for non-dairy drinkers to enjoy in their latte (you can experiment in the same way with cappuccino but may have difficulty creating proper foam), as well as offering house made syrups for flavoring.
Flat White - an Australian hybrid of a cappuccino and a latte, the flat white keeps the two to one coffee to milk ratio, but the milk is stretched and textured through heat to create a drink which has more volume and a different flavor than your standard latte, yet is less foamy than a cappuccino.