Typically, laws allow for darker tints the further back the window is (rear windshield can be darkest, then rear windows dark, front windows lighter than that, and then no tint on windshield). If you abide them, you typically have a pretty decent looking tint consistency (at least in TX). By having the rear windows darker, there is already less light coming in from a majority of the windows so there is only discernibly higher visibility through the front windows from certain angles.
Also, be mindful of how much your visibility looking out will be impaired at night by the darker levels of tint. Having darker tints in the rear don't affect you as much as those of the front windows. On one of my cars, I had "limo"/5% (police read it at 2% when I was pulled over) and on another I had legal tint (35% at the time) + 5% over it because I thought the OG was too light... At night, seeing outside of my windows on both was impossible. All I could see was a slight dot of light from other cars' lights.
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Not to derail, but does everybody go with a straight black tint? I had "titanium tint" on one of the cars I mentioned in here and I thought it looked good. The titanium being a dark charcoal-like color tint... kind of gave it a glossier look. I think the green/mirror tints are tacky, but that titanium didn't look like that. Still have no tints on my new car and unsure of what to get but need to do it soon before the heat gets ridiculous.