Get to know and use the paper Effective Blood Pressure Log.
It is the only one with diagrams that you fill in to have the clearest picture of the evolution of your pressure.
Each log page can hold up to 31 measurements, i.e., one month, for better comparability.
Also, it has instructions for use. And much more. Explore!
You can view it in pdf format and then download it for free and print it using this link.
Or you can view it in Amazon’s “Look Inside” and buy it, it costs $7.5 € and it is for five years, using this link.
Take care and best wishes!