Know that you know what percentage of tint is allowed by your state, next step is getting the window tinted. Next decision you need to make is whether you want a cheap and low quality window film, or a high quality one?
This can be tricky, because low and high quality window films both look the same at the beginning. But overtime, you will start to note the differences between the two. Cheap one will start to get purplish, fade-out, get all “bubbly”, and wear out. That would leave your windshield looking all messy.
If you are planning to keep your car for a while, let’s say more than a year, I’d suggest you go for high quality film. Ask different shops and question them about the quality. See if they offer your any guarantee.