Bananas are good, berries and most leafy green vegetables. Avocados, sweet potatoes, nuts and legumes.
Switched to potassium-enriched salt for cooking so no-one else in the household has to suffer bland food.
Beetroot juice (+ apple & carrot to counter the acidity) is also something you could try. Actually good for your blood flow with potential flow on effect for your BP.
Personally taking Omega-3 and magnesium supplements.
I read somewhere that the potassium in bananas is supposed to decrease BP. Which seems strange given that sodium is supposed to decrease it. Aren't they chemically very similar?