Invisibility magic is very tricky, and I think very overestimated much of the time. You’re not going to up end the laws of physics and cause light to stop reflecting off you and into the eyes of others. However, with a bit of practice and some magic, you can walk as a shadow, silent and unnoticed.
The first thing to understand about making yourself less visible is that it is more in how you carry yourself. Practice making yourself smaller, less significant. Slump your shoulders lower your eyes, let your body be loose, stroll casually. Visualize yourself blending in to your surroundings. These things do the bulk work of making you less visible.
Once you’ve practiced that enough that you feel comfortable, begin chanting the spell below while in that state. It will form a connection between the altered state and the words, so that eventually when you speak them, you will fall right into that state.
Finally, whenever you feel the need to disappear, recite the spell and imagine shadowy mist engulfing you, shrouding you from view. You’ll notice people will look over or through you, or avert their eyes entirely. Making direct eye contact with others will break the spell, so avoid it the best you can.
Here’s the incantation:
Shadows rise and shadows fall
Shadows all around me crawl
Shadows shroud me as a cowl
Shadows come conceal me now.
I’ve been using this spell since high school where I designed it to avoid being caught for dress code violations in the hallways. You can even cast it around an area if you get good enough at it. I did so once when we were cutting circle in my backyard to keep the nosey neighbors from running over with torches and pitchforks. When my friend was dropped off, she said that from the road, it appeared as of we were grilling, rather than setting up an altar. Haha