thinners

Most hardware or alternate thinners miss one vital ingredient and that is the "retarder/extender" this is what makes the real difference when airbrushing and even brush painting. Most of those cannot be identified by just smelling the thinner.
Those are also often sold separate or at arts-supply stores.

The retarder extends the drying time of the paint and thus allows paint to flow better together when brushed(less streaks, etc), in airbrushing it will help prevent orange peel effect which is caused by the atomised paint drying before it hits the model.

You can try it for yourself, take your current alternate thinner and mix in a suitable retarder for your paint(enamel, acrylic). Or use Gunze standard thinner and leveling thinner.

Lack of retarder and and insufficient stirring of paints I found to be a major cause of many paint and A/B related headaches.

enamels

ACRYLIC OR ENAMELS??

It sounds like you're describing acrylic thinners.Although windex would probably be considered a cleaner more than a thinner.It all depends on the company, I thin Tamiya with Iso.97% and dist water and have good results.Others swear by manufactures thinners.I saw not only in this forum but others that auto winshield fluid thins Gunzie very well.Still there was a thread about using laquer thinner for Tam.Now when you get into enamels or oils you have to use mineral spirits or other dist. based thinners.Each manufacturer has it's own but many found at hardware or art suppliers work well.