I'm not sure if this tiny parapet constitutes a balcony but it's better than having no outside space on the sunny (south) side of my flat.
My balcony is a real sun trap so this year I've planted pots of blue flowers and a container of pink tulips. I also have a David Austin rose bush that I bought at the end of last summer; it should be in flower in a few weeks, hopefully. It's a gorgeous rose called The Pilgrim. The flowers are certainly attracting the bees.