Tell me how to make onion rings and deep-fried mushrooms with the crispy but a little airy, a little bready.?

I am a pretty good cook for a guy. I have fried different things in a pan with the rinse-it-in-water, pat it, then plain flour, plain corn meal, Bisquick, different cajun batter mixes, etc. I've done all the same with eggs, milk, eggs and milk mixes, etc.. I bought a nice deep-fat frier with a sensitive adj. temp switch. I want the recipe for the onion rings and mushrooms that have the crispy outside, a little bready, but fluffy inside, like an 1/8" fluffy coating, you know. I can get a tasty, but thin, or missing in spots,flat, crust that also falls off often, not like the restaurants or even, FROZEN, which are nasty otherwise. Corn breading is fine with me, if it is a nice crust like I said. I love a steak, with deep-fried Onion rings and mushrooms occasionally, but my deep frying is not that great. Corn meal, spicy, whatever is fine. Thanks