Sit outside when the sun is shining, and it will be easy to visualize it, as you already see light.
If I don't sit out, sometimes I visualize myself from a third person view, and that way I can visualize myself glowing more easyly. (this is just personal)
Also, after you vibrated a sun mantra, affirm a few times, that this energy has cleand/cleaning your aura, and your aura is shining Somethimes when I say my aura is shining, or this energy strengten my chakra, then it is more easy to visualize it, or maybe your brain will visualize/feel it automatically-.
To see it more efficient vibrate more, affirm more times, practice more, be in a deeper trance.
Keep in mind, that that's can mean an upcoming sickness, that you cant visualize light.