Techniques you can practice immediately are The Journey, which is the easiest and most important mnemonic and Linking which is adding a linking story to the loci (place) in the Journey.
Choose a simple journey, that of your own home, and pick out strong visual points of interest eg:
Bedroom – you can break this up into bed, wardrobe, window, dresser, etc
Bathroom – you can break this up into bath, shower, washbasin, toilet
Stairs – if you live in a house.
Hall – leading to
Kitchen –break this up into stove, sink, table or counter, cupboards, dresser, window, and door.
Sitting room or sitting area –break this up into tv, sofa, chairs, table, cupboards
Front door
Garden
Street.
Use a linking story at the chosen location points to help remember details of what you want to remember. If you want to remember ‘banana’ then fill the bedroom with bananas and eat one, imagining how it feels, smells, and tastes. If you then want to remember ‘elephant’ then wade through the bananas to the wardrobe and place an elephant inside.
Engage movement and all 5 senses into your imagination: sight, sound, touch, smell, and taste with a bit of humour, and finally add some music to accompany the scene.