Making cocktails can be super busy and sometimes, when you host a party, maybe celebrating your birthday, making them while drinking a lot is a no can do. That is why we use "bowla".
Choose you cocktail, but be careful, if you and your friends are about to drink a lot, do not choose too of a sweet cocktail. I usually make more than one bowla, and on of them is always gin based Tom Collins. It is so refreshing, not too sour not too sweet, it's kind of an alcoholic lemonade. And if you have a dancing kind of party, Tom Collins is great for your thirst.
My next bowla is always something with Blue Curacao, usually Blue Lagoon. Friends are always amazed by its blue color and dancing with a glass of blue lagoon is always great seen on photos. This is not the best tasting cocktail out there, so serve this bowla after your friends already had something to drink (when they won't be all about how good it is, but how good it looks).
My third, and usually last bowla of the night is actually a non-alcoholic version, so a mocktail of some cocktail. I don't go around telling friends it does not contain alcohol, I only say it is an easy drink, so we will all be able to sleep. A sweet non alcoholic Sex on the beach comes in handy now.
So that way your friends get to experience a really great tasting and refresing cocktail (Tom Collins and similar cocktails), a really great looking cocktail that will make a night worth remembering (Blue Lagoon or any other Blue Curacao cocktail) and some sweetner (Sex on the beach, etc), which will help them sleep and wake up with some less hangover.
A tip: prepare all your ingredients in advence. After you have had some drinks, you might confuse some ingredients, so squeeze your lemons, make your ice, get your alcohol and juices somewhere together... etc
Another tip: making ice - don't put ice cubes, crashed ice, ice-maker ice in bowla. This is way to small for a bigger amount of liquid. Just take some clean empty container of ice cream or something with at least 1 liter hold, pour in cold water and put in in freezer for a night. You can add some cut lemons and oranges for a better look. I have a 8L bowla and I use big ice cube of 2L ice cream container.