Perhaps you'll know from the moment you awake and don't want to disturb the cat on your feet. Perhaps the rain on your bike helmet will be a little too loud. By midmorning you'll find yourself soaking a couple of pounds of navy beans in four times their volume of water. After work, you'll drain, rinse, and put them to simmer in a great big pot (with fresh water -- the digestive advantage in soaking your beans will be lost if you don't change the water!). You'll add the tomatoes -- lots! -- and starting browning several onions in another skillet in plenty of butter or olive oil. If you're not cooking for your vegan friends, throw in all those ham bones you've been collecting in the freezer. Be careful not to add anything salty (like salty canned tomatoes) till the beans are cooked; salt toughens bean skins so they take longer to get soft and then split when they do.
When the beans are well on their way to done, add the well-caramelized onions and chopped carrots, celery, and garlic, and anything about to die in the crisper. Then go reconnoiter the spice cabinet.
I'm sure it's not a new analogy, but mixing spices is a lot like mixing paints. Sometimes you get purple and sometimes you get off-gray. Too many flavors "confuse" the palate. There are some wonderfully complicated, even baroque exceptions; namely, Indian cooking, and rainy day soups. It helps, of course, to have some sort of theme in mind. I like smoky red things like paprika and chipotle in my bean soup, maybe a little tangy sumac and green stuff like sage, oregano, and thyme. Grind black pepper on everything. Remember: when all those poor mercenaries died in the Crusades, they weren't dying for the grail or gods. It's always been all about pepper.
When the beans are really soft, it's time to go into labor. First check the texture of the soup. If it's too thin, pour some of the broth into another sauce pan to increase the total surface area, and boil both pots to the desired consistency. Next, add several tablespoons each of salt, molasses (or brown sugar), and cider vinegar. Thirdly, assess the "mouthfeel" of the broth. If there are bones in it, they'll add that nice silky gelatin finish, but if it's vegan, you'll need to add something saturated, like coconut oil. Fats mellow and blend flavors, so if the acid gets out of hand, counter it with fat -- just the way salts and sweets counter each other. Taste and edit wildly-- this is the fun part! Remember to cleanse your palate with wine between each tasting. Consult with your housemate -- she'll be your midwife. Taste again. If it just needs something ineffable, keep adding the sweets, salts, sours and fats till a spoonful of the broth is like ten cats on your bed, fifty good books, and a hundred thousand steaming cups of tea.
Vegans: Bones add savor from sodium & other minerals, and a nice rich texture from their gelatin content. The clever vegan will remember to add extra extra salt and swirl in a goodly-sized chunk of coconut oil at the end to make up for the absence of bones.
Serve your baby with cornbread for the complementary protein synergy. (Complementary proteins: grains & dairy, beans & rice, corn & beans, pie & ice cream, wine & cheese, coffee & cigarettes).