This is not a recipe. It's not going to tell you what to put in soup; it will tell you how to deal with whatever you want to put in soup. 
It doesn't work for all styles of soup, but will pretty much give you a soup whatever you put into it.

1: Frying onions
	Get hot fat. Oil/butter/ghee/whatever. You don't need too much.
	Start onions frying. (also celery, carrots, if you like).
	I don't really put garlic in soup, but if you want to, now is the time.
	Any spices you want to use go in now.
	Turn the heat down; you want to brown, not burn.

2: Other veg
	Most other veg goes in now, hardest stuff first;
	e.g. root vegetables and brassicas want frying for quite a while; spinach or watercress will want only seconds.
	If you're putting in lentils, they go in now too.
	Prepare in order - add the hard stuff and let it fry while you're chopping and cleaning the softer stuff.
	Add more oil if necessary to prevent sticking, but not more.
	Stir every few minutes until you are bored.

3: Add cooking liquid
	Hot water, plus liquid stock, wine, beer, juice, or whatever. NOT milk yet.
	Taste it, make sure you're not making it too strong-flavoured with stock or wine.
	Simmer. Cover the pan, it'll cook faster and be more energy efficient. Keep simmering until everything is soft.

4 (optional): If you're going to blend the soup, do it now. 
	I really recommend hand-held blenders, the sort where you stick one end in the pan and press the button on the other end.
	Also, I prefer not to blend until it's a homogenous goo; I like some texture.
	It's fine to pull some stuff out and re-add it after blending the rest, if you want some whole peas in your pea soup, or whatever.

	I'd put tinned beans or dried barley/rice/pasta in at this point (assuming you don't want them blended!)


5: Simmer more, add seasonings
	Taste it first.
	If you're using powder/cube/paste stock/miso, add it now, mixing well and tasting as you go.
	If you like: lemon juice, pepper, more wine or beer.
	Similarly: tomato puree/juice, dried herbs.
	There's really no rush; you can keep things hot for as long as you like, or let it cool and reheat it later.

6: Turn down the heat, and add the Delicate Stuff
	Milk/cream - don't boil it vigorously after adding this
	Fresh herbs, lemon zest

7: Heat without boiling for a while, then serve.