A few decades ago I was diagnosed with hypertension (high blood pressure) and for about the last 15 years I have been tracking my blood pressure and weight. Every morning when I wake up, I weigh myself and take my blood pressure. I write the results in a CSV file that sits on my desktop (it gets backed up). I do this religiously, every single day. I have tried other, more "modern", solutions but somehow they don't stick or are too cumbersome to use. Even tried to build my own app but lost motivation at some point.