* Learn what common and abbreviable (I'm not sure that this is a real word) words are, and abbreviate them.
* Create a system of declensions similar to German or Latin -- you could probably drop a lot of prepositions this way.
* Use symbols if they're easier/faster to write.
* Leave space to create a legend, explaining abbreviations or symbols made up or allocated on the spot.
* Leave lots of margin and whitespace.
Nothing very comprehensive, I'm afraid. I'd be interested in seeing a more-developed system too.
* Learn what common and abbreviable (I'm not sure that this is a real word) words are, and abbreviate them.
* Create a system of declensions similar to German or Latin -- you could probably drop a lot of prepositions this way.
* Use symbols if they're easier/faster to write.
* Leave space to create a legend, explaining abbreviations or symbols made up or allocated on the spot.
* Leave lots of margin and whitespace.
Nothing very comprehensive, I'm afraid. I'd be interested in seeing a more-developed system too.