as a seasoned stocking/holdups wearer (having very long legs and finding tights, therefore, to be the most uncomfortable thing in existance), i have a little 'in the know' tip for you girlies.
instead of wearing stockings with your suspender belt, wear hold-ups with it. That way, you have the extra grip factor of the sticky part, but the security of the suspender belt lest the grip slacken.
it works