This is what I did (now it helps I live with my MIL who is a doctor). We have a good blood pressure monitor at home. I checked it several times a day to figure out when it's the highest for me (usually around 4-7 pm). So, I take it then. And I just watched it fall. When it got to be like 105/60 consistently, I started dropping dosage. I started at 40 mg of lisinopril in January and was able to get completely off meds with exercising 6 days a week and dropping 50 pounds and in 5.5 months. I no longer need blood pressure meds.
My intake went like this: 40, 30, 20, 15, 10, 5, none.
Of course, don't do this on your own volition, but do check regularly and consult with your doctor if you notice your BP coming down significantly so he/she can adjust your meds.