Smoosh up the berries in a plastic baggie. With your hand, or a rolling pin. You can use really any berry you want, just cut leaves off and rinse them.
Add equal parts lemon juice and sugar to a pitcher. Start with half a cup or less (less sugar than you normally would like) and then add the smooshed-up berries. Taste the lemonade, and add a bit more lemon or sugar, to taste, until it's perfect.
I'm sorry, lemonade is not a perfect science. But it is an easy one!
And a pretty one.