Incorporating organic matter

Whilst I'm thinking of organic matter ... I presume some / most of us garden to a good degree along organic lines. I've seen it said that the biggest mistake with organic growing is to not only stop adding chemically made fertilisers, but to stop adding anything at all ! So I need to add more organic material to my plot, but when is best, and how ?

I've previously double dug it in in spring. Backbreaking work, and the ground turns quickly from sticky and heavy to very hard as it dries out, leaving a narrow window of workability. Now, some recommend applying manure as a top dressing in autumn, to let the worms do the work of incorporating. I have assumed (perhaps unkindly) that this was born out of a combination of optimism and laziness, but having tried it it did seem to make the preperation of the ground for planting in spring much easier; the underlying clay soil did not turn to concrete quite so quickly.

What do you do ?

I only really produce enough compost to properly top dress one raised bed in the autumn, so the other beds either over-winter with crops like Spring Greens, or I sow green manure if the bed is empty.
I do use Blood Fish and Bone as well, in the Spring before planting - I know there's some debate about this, but that's what I do anyway!!

I'm fortunate to have a permanent supply of manure from our muck heap (mostly cow/straw) - on request it gets delivered by jcb bucket over the fence. The worms do do a good job if it is spread on top - I could see this in the polytunnel when I put a good few inches on top of heavy clay last autumn. I was surprised just how much had been incorporated by the time I came to plant. My outdoor beds haven't had too much attention over the last few years and it is showing. So, as I am digging each row of potatoes I am leaving a trench and filling it with manure then putting the soil from the next row of potatoes on top. By the time all the potatoes are dug I will have two well manured beds without any extra effort.