1) Detail matters.
If you've seen my book, you notice how I'm careful to be highly specific when I need to be? That's because if the details are wrong, people get pissed.
You can never be ambiguous. Also, you can't guesstimate EVER. Because there will be that one guy out there who uses a measuring spoon. And who doesn't trust himself to cook, so he'll follow your directions to the letter.
2) Your work flow matters.
It may seem natural for you, but it's not to people who don't cook. For example, if I'm making a soup with cabbage, I'll start the water boiling, and have the slow cooking veg in the pot before I even touch the cabbage. Because the cabbage cooks fast, and goes last. So it's more efficient to get my pot going first, and then do anything to cabbage.
But people who don't cook? Will literally prep all the ingredients first, and have them laid out. And go through everything one at a time. Four hours later, a meal will be on the table, but they'll think that vegan food takes forever to prepare.
3) List ingredients twice.
Once in the ingredients list, and once again in the recipe itself. This provides a cross-check for you as well as the reader. Never say "the dry ingredients" or "the spice blend".
Re-list the spices, one by one, so that when you're done writing the recipe, you have a handy cross-checking tool. Also, never ever call for something that you didn't ask for in the ingredients list. It'll make your proof reader and recipe reader yell at you.
If you need 1 cup of water to boil the peas in, make sure that you list water as an ingredient. If you need additional water at the end, reserved just in case, account for that in the list, and say where you'd use it.
In cases when you'll need to add different amounts of the same ingredient in two places during cooking (add additional oil), list it in order.
For example: 25 mL canola, peanut, or sunflower oil, 3 grams cumin, 3 grams coriander, 1 aubergine, 10 mL canola, peanut, or sunflower oil, etc.
4) List ingredients in the order that you'll be using them. As in, if you're pouring oil into the pot to get things started, the oil you use to get stuff started goes first.
I'm also referring back to the point about being specific. If you want them to use canola oil, say so. If they can use peanut oil instead, say so. If you don't want them to use margarine, shortening, or olive oil in place of canola oil, mention it in the intro what recipes don't matter what the oil is, and which ones do matter.
Testers.You'll need to come up with a crack team of testers, either online, or in person. They need to be able to do a couple of things.
1) Be able to follow your directions to the letter.
2) Take specific notes on the process, and how it turned out for them.
take notes on timing, on measurement accuracy, and success of the instructions. Make corrections as needed (if they're a good cook), or follow through and fail (if they're a beginner) and yell at you.
3) Give specific feedback on taste, texture, ease of preparation, and total cooking time, including prep. You'll need that last bit of info for the top of the recipe.
And finally, they need to tell you if they'd make it again. If not, why not. Because recipes that are only used once and then never touched again will take up needless space.