Take a few minutes to relax by sitting or laying in a comfortable position and then breathing in a slow, even manner. The Four Fold Breath may be used for this purpose. Work at making all aspects of yourself feel calm and relaxed. If you can sense any energy/emotional tension anywhere in your body, slowly work at relaxing it. Visualize all tension melting away from you as you relax completely inside and out. If it helps, you may slowly tense each muscle in your body one at a time (starting with the head, then shoulders, then arms, hands, abdomen, legs, feet etc. in that order) and then relaxing it. If this isn't effective for you, you could try tensing every muscle in your body simultaneously and holding your breath while counting to ten and then relaxing again if it helps you to loosen up and relax before beginning meditation.
When you are completely calm, and still breathing slowly and evenly, then visualize yourself not as just a human figure sitting or laying in your room, but as a white (or gold if you prefer) orb of light that extends beyond your physical parameters. Try to feel yourself as this luminous egg of light.
Gradually increase the size of your imagined self until the orb of light which is YOU fills up the entire room you are in. Try to feel your aura interpenetrating everything that is in the room with you.
Now increase your imagined size again until it engulfs the building you are in. Try to 'feel' yourself becoming the size of that building and interpenetrating everything in it.
Increase your size further yet to that of the city you are in, and then the country, and finally the Earth itself. Keep expanding your imagined size until you are so vast that you flow seamlessly into all things and through space.
The idea is not to imagine your ego to be expanding until you are the ruler of the universe. The goal is to expand your sensation of yourself until you become ONE with the Infinity that flows within and throughout you and all things. You should eventually endeavor to feel yourself as being like one water droplet within a vast OCEAN of Allness; not being distinguished from any other drop, but still sensing and experiencing oneself as part of the Ocean of Infinite Allness itself. Eventually concepts such as size won't matter as you progress in your meditation. All things will appear to be relative. Logic and reason will be surpassed. Ego and 'self' will be of little importance in that state of realization and sensation of the infinity and interconnection of All things.
Stay for a few minutes in that state of sensation where you are One with All things and part of that Infinity that interpenetrates all things. There is no ego or self in this state, only Selfless Allness.
When you decide to end this meditation, slowly retrace your steps of visualization. Return to being the size of the Earth, then your country, then your city, your building/house, your room, and finally your normal size. You should retain this feeling of Oneness with all things and calmness of mind. Practice this meditational exercise frequently to enhance your psychic and spiritual development.