I would say that the preferred method would be to stir the cup as you grab it, I am not trying to be a jerk, I know what you are talking about and I take my cup when ordered and shake it a little myself, its very easy.
Ke kopa Mme a moholo e be nyatsi yaka ke le mong fela,a sa tlo nsokodisa ha ke lakatsa kuku, ke tla o betjetsa le nna.pls e be Mme a ratang sex too much.