I made a rough square wooden frame for my outside toilet tent spray booth so it could live on the patio and not on the lawn. Stuck an eyelet at each corner and tied the tent to those. Stops the tent blowing across the patio in light to medium winds. In stronger winds I put some cast-iron framed gargen chairs on the frame to keep it in place, but on a balcony, you shouldn't have too many issues like that (though a good rope tether to some railings or similar would be a good safety precaution).