#1 What is the occasion?
Is it a party, is it a wedding, is it a funeral? Knowing what sort of occasion it is will help you to understand what’s suitable. For instance, if it's a bit of a knees-up, the chances are you might want to stock up on drinks whereas if its a day-time family event, you might need more low-alcohol or non-alcoholic options. The more you think about what your guest might like to drink, the better prepared you will be, which leads us to the next tip...
#2 Who's coming?
Are they big G&T drinkers, wine drinkers or cocktail drinkers? This is pretty definitive as the selection is always the key to satisfying everyone as best as you possibly can. You are never going to perfectly provide for everyone's tastes so the trick is to understand some key staples when making approachable beverage choices.
G&T’s and spritz's are a great idea here, otherwise, a simple punch can often get the communal spirit going. For the connoisseur crowd, another good option is to have some spirits to choose from available for making the likes of Old Fashioneds or Bucks. A tip here is to always have some alternatives up your sleeve should your planned beverages not be everyone's cup of tea, a good solution is to have multiple uses for a couple of the drinks that allow you to lengthen them or simplify them, for example topping a Daiquiri with tonic to make it a long drink.
#3 Time & Place
Suit your drinks to your location and weather, long tall refreshing drinks for outdoors and hot weather, warm spice-driven and comforting drinks for cold situations. On this, the seasons can work to your advantage with your ingredient selection and with some research you can make use of local seasonal fruit and garnishes.