Internal memory strategies are things you do 'inside your head' to remember things better - for example, thinking about something in a particular way or trying to visualize something as an image or story.
We all use a variety of ‘external memory strategies or 'tools’ to help us remember things, whether we have had a brain injury or not. We might make notes, keep a diary, use a calendar, keep a filing cabinet, or just have a well-rehearsed routine.