The word abbreviation comes from the Latin word brevis which means short. An abbreviation is basically when you make a long word shorter (instead of “Human immunodeficiency virus” we simply say “HIV” etc) so is there an efficient way to abbreviate words in general?
In my opinion, you should try to develop your own style of abbreviating long words (when taking notes that is). I mean, you are the one reading the notes right? It doesn’t really matter how you abbreviate the words as long as you understand the notes.
But then again, the title did say “How To…” so I suppose I have to give you some guidelines now anyway, right? 🙂
I recommend you to check out this article from The University of North Dakota’s website. Although I think you should learn to abbreviate in your own unique style some of the tips that are mentioned there are worth looking in to.