I carry a notepad and pencil with me to jot down ideas. The problem is, my handwriting is so abhorrent that often I cannot decipher what I wrote.
How can I write more legible?
I'm not sure that learning to draw pretty letters will help. In elementary school we had a course that was called "writing beautifully" (Schönschreiben). The kids learned to write well-formed letters and received little presents when they did well. When I was in fifth grade, my handwriting had become so illegible that I stopped writing the cursive script I had learned in elementary and started writing printed block letters (by hand, that was before computers). But my handwriting deteriorated quickly again, and today I can barely read what I write. I'm too impatient to write more slowly than my thoughts pop into my mind.
I have obviously tried the answers to this previous question, and they didn't help. The problem is not that I cannot write legible, but that I don't. Training calligraphy again (for the third time in my life) won't keep my handwriting from deteriorating again once I stop doing the exercises or stop forcing myself to write slowly. These are not solutions, because I don't have the time nor will to do handwriting exercises consistently over the rest of my life.
Other people have legible handwriting without doing exercises. So please don't recommend them, I'll downvote such answers.