Note-making is a highly-valued writing skill most commonly used when listening to speech, although it can also be used as a reading/learning aid. The idea is to generate self-study material which helps connect concepts, and from which to draw conclusions.
Using abbreviations and listening out for some of the most common signpost words and phrases such as for example (e.g.) or that is (i.e.) helps save time/energy. Another useful way is to make up your own abbreviations as you go along, as when texting, but making sure that they are easily identifiable when you read your notes later. This is typically done by leaving out the vowels of words, e.g., cntrl = control.
Note-making vs note-taking
There is an important difference between note-making and note-taking. The latter is a passive skill, i.e., a receptive skill, basically limited to putting down on paper (quantitatively) what is being said by another person, while the former is a more active skill, i.e., a productive skill, involving the summarising and processing of the information received.