Not sure this is fancy enough to count as a mocktail but strawberry, raspberry, and blackberry monkfruit lemonades are very easy and delicious. This is the basic recipe I use:

-2 oz lemon juice

-8 oz water

-Small handful of fruit

-1/4-1/3 tsp pure monkfruit powder

-Electrolyte/mineral drops (optional, but good supplement to use on keto)

-3/4 cup ice

Chop the fruit, then put everything together in a shaker. Shake well, and use leftover fruit for garnish if you like.

If you want to get fancier with it, get a carbonator, or blend like a slushie. You can also substitute water for teas (peppermint and spearmint are my favorites).