I think one of the prettiest ways to garnish cocktails besides fruit and herbs is edible flowers. A veritable bouquet sits atop this gin martini and Lillet Blanc cocktail, while egg whites provide a frothy finish.
Make a large batch of the Summer Strawberry Flip Cocktail for a crowd pleaser -- 2 oz Wild Turkey American Honey Whiskey, oz lemon juice, oz strawberry simple syrup, 1 egg white, dash bitters + strawberry garnish.
I like the idea of having a champagne bar. Especially if the favors are champagne bottles. The restaurant does like a 'champagne punch' that we can put on a table with a cool like chalkboard sign or something? And also have the favors on that table too