I agree that reducing the sauces down makes for better flavour, works the same way with everything even a tin of soup.
The bhoona or cooking out the spices is just as obviously right as well.
Technique is definitely important, as is taking the time to do the recipe justice and not cutting corners ie, not bhoona'ing to save time, not reducing to save time etc.
Practice and repetition.
We have a quandry though, say i have 5 local curry houses, they all cook the same dishes they are all different, why? because they have different chefs, with different techniques differeing amounts of patience and the odd one or two who couldn't give a toss and just want the wages and to get home.
I suggest that we here are the same to a certain extent, when i try a new recipe i read it through, then i have a think about things a bit, then i read it through again, and probably a few more minutes thinking, then some more reading...I take care to follow the recipe, but then i'll change things as im going along

ill add a little of this and remove a bit of that. Because i know what my tastes are and thats my aim.
If the phone rings i'll take the pan off the heat and go and answer it, thats not in the recipe.
SOme people will read the recipe once and then make the dish, some will alter things some won't, some might have a phone call some won't but all this makes no difference because they are not cooking to MY tastes.
Were all different, we'll never make a uniform curry.
This site proves this, we have real chefs recipes here, conspiracies aside, they are all using the same ingredients, and the only difference is the chef and his technique.