Step 1: Filter the information
Don't copy every word, but note only the expressions and key ideas you'll need to prompt your memory.
Step 2: Classify the information
The substantive content of the lecture consists of concepts and factual material. This may be accompanied by references to various works, which you should consult. Usually, concepts are illustrated by anecdotes and examples. You will record each differently.
Step 3: Organize the information
You should adopt a formal plan for your notes to make them as clear and consistent as possible. This will save you time later!