I take a half bushel of hungarian hot wax peppers, a quarter bushel of jalepenos and a quarter bushel of cayenne and a pint of habeneros for mine.
Wash them, seed the wax peppers and pop the stems off the jalepenos and habeneros then cut them in half.
Toss everything in to a food processor with a half cup or so both white and cider vinnegar with a pinch of salt.
Process until about pickle relish consistency.
Then I cook it down in a big stock pot for about an hour and process again until smooth as I feel like getting it adding more vinnegar till the consistency I want is reached (usually another half cup to cup of each vinnegar).
Then it goes back in the stock pot till it hits a boil then I just keep simmering it in the stick pot while I jar it up (boiling water bath method, there's so much acid in there I'm not worried about anything bad surviving).
It's a little sweet from the Hungarian peppers and the cider vinnegar but plenty hot.
It's thicker than most sauces. More like Thai chili sauce.
ETA: garlic and onion. I use a few cloves of whatever variety of hard neck garlic I have handy and toss in a spring candy onion (not sure what they are but that's what the grumpy old dude at the farm market calls them) that I've had sitting around all summer. Or a vidalia if you can find one. Otherwise any smallish yellow onion.