How much to water partially depends on your medium. Water-to-runoff is only good if you have really well draining soil. Too much clay or peat and it’s just going to hold so long the roots rot. I like having about 20% fresh coco coir in my soil, but it also originally had some, plus pumice, perlite, and native soil.
Coco mixed inseems to keep my plants happy even when the soil feels like it is getting dry (I lift the pot and it is light). I test with a Rapitest moisture meter occasionally but just to get really deep to track moisture low. If it reads 2.5-3 or less I water using a mister or that setting on hose-head, or the lightest of showers. Misting takes time but is the best because the water gets better aerated (roots need oxygen!) and it doesn’t move your soil around causing your light material (perlite) to float. You want your nice, airy soil to stay nice and airy.
On that last note, some people use just a mix of coco and perlite, or just one or the other.
They both drain very well (though coco’s micro-pockets help hold air and water that your roots can access it dries) and these mediums when just them should be watered until runoff.