My hypnobirthing coach, who is also a midwife, told me to do 10 sets of 10. Try and tie them to something you do regularly each day, like every time you sit down do a quick set of 10, or if you're driving a lot, everytime you pull up to a traffic light. But most importantly she said never do it while you are on the loo, do it before or after, but never while you're actually weeing. If you stop the flow you could cause some urine to travel backwards up your urethra which can in turn cause infection. So please be careful.