See five things: notice the colours, shapes, and textures of your surroundings. Look for the colour variation and texture that may have gone unnoticed.
Touch four things: notice the sensation of where your hands meet something solid like the fabric of your clothes, objects, your skin
Hear three sounds: notice and listen carefully for the different sounds around you
Smell two things: Now shift your concentration to noticing the smells. Try closing your eyes to pick up the subtlest of scents.
Taste one thing: notice your tongue in your mouth, run your tongue over your teeth and cheeks.