There are so many fruits in the summertime, so you are bound to find ones that everyone can love. The ripest summer fruits are blueberries, blackberries, raspberries, pineapple, mango, papaya, watermelon, cantaloupe, lime, peach, cherry, and lychee, cucumbers, plums, nectarines, for those of you wanting some more adventurous fruits.
Keep it simple. Everyone loves lemonades in the summertime, so simply make a homemade lemonade, add some vodka (about 2 oz per drink) and put a twist on it with a summer berry like blackberry or blueberry. Just puree the berries and add it to the lemonade and your guests will go crazy for it.
To be more adventurous, add combinations of fruits since they are so many great summer ones. Try combinations like: Watermelon & Cucumber, Cherry & Lime, Blueberries & Lemons, Strawberry & Basil, Blackberry & Mint. Your guests will be amazed at how well these flavors work together and how creative you are.
If you want your guests to have some extra cocktailing fun, create a "Make Your Own Mojito" Bar. Put all the ingredients needed for a regular mint mojito and then put out bowls of summer fruits, such as pineapple, papaya, raspberry, watermelon, almost anything will work. At each part of the table, write an instruction for that step of the mojito. As your guests try it, they will have tons of fun creating a cocktail that is specially formulated for them AND you don't have to play bartender at your own party.
Invest in a bar muddler. You can find muddlers at any major liquor store usually or any kitchen store. A muddler simply allows you to "smash" some fresh fruit and keep summer cocktails fresh and exciting. A simple spiked fresca is great for the summertime and is only vodka, fresh fruit muddled and some soda water. Add sugar for sweetness.