Try out Forker shorthand. You can learn it gradually, and the first steps are omitting vowels and simplifying some letters. You then progress to various abbreviations. Ultimately, it's based on the English cursive so there's nothing too exotic to learn in terms of orthography, although I guess if you are younger there is a chance you never learned a cursive style! I'm a novice but feel like it doesn't hurt readability that much, and it's quick to learn.

Quick intro: https://imgur.com/a/zYyON