Make sure you're eating plenty of salt. Salt helps your body hold on to fluid, which in the case of uncomfortably low BP is a very good thing! Also take care if you stand up quickly, or in taking very hot showers, which can increase dizziness.
My BP always runs 80s-90s/50s-60s, as does my mom's, and we both experience periods of dizziness if we don't keep up w/salt intake.
The good news is, that aside from potentially taking a fall b/c you're dizzy, low blood pressure is an extremely good sign in terms of heart and kidney health! I work w/cardiologists who are always pleased w/BPs like this!