Be Selective

The key to making good notes is to be selective about what you record. You won't be able to record every single detail of what is said in a lecture or seminar and taking copious notes from a book is a self-defeating exercise.
To make selective notes record the key points, and underline the most important terms.
Also bear in mind your reason for taking notes, what function they will serve. There is little point in making notes on a lecture or seminar which repeat material which is given on handouts. In these cases you would be better making fewer notes and concentrating on the things which really interest you. Likewise if you are making notes from a book, ask yourself why you are making them. If the notes are to help you remember what the book is about they may well be different from notes made when you are looking for references to support a particular section of an assignment.
Experiment with different styles of note-taking and recording. Some people have minds which work well in pictorial or graphical ways and they often find that recording their notes in the form of spider maps or concept maps can help. Others prefer notes arranged down the page but develop their own annotations. Remember that unlike other forms of writing, note-taking is really to help you and you alone. So there are no conventions or rules to follow, be guided by what works best for you.

Revisit notes

Whatever your style of note-taking, one technique will help you get the most out of them, and that is rereading and revising your notes. After a seminar or lecture find a time to sit down and reread your notes. Anything which isn't clear from your notes will still be held in your memory, you can then amend your notes so that when you need them at a later date, they hold the maximum of information.
When you have amended the notes make sure that they are headed with the title of the session, the date and other relevant information and file them carefully. You have made them as an aid to memory so you need to make sure you can find them when needed.

Using the Library Referencing