Vegetable beds will often benefit from being left to lay
fallow for a few months now and again – and it makes sense that its done over
winter.
Inevitably though weeds will accumulate so its good practice
to be disciplined in your preparation for re-planting when spring approaches.
Some gardeners recommend digging weeds back into the soil,
based on the idea that all nitrogen is good for your garden. This is true but the seeds will just
re-sprout as the soils warms up and any perennial roots can re-sprout, so you
have no choice but to remove them. Weed
seeds will also survive the heat and decay of the composting process so there’s
only one place for them and that's the garbage.

All good veggie plots should have a good worm count and some
say that the work they do is better than digging.
I disagree with that as worms cannot quickly
inject large quantities of new air, break up heavy clods and most importantly
they’ll never get rid of other debris and live pests like curl grubs.
Good friable soil needs to be dug over once a year and it's
a great time to also add plenty of new compost.
You can use a spade or a fork, but dig in straight lines,
don’t dig too deeply and turn the soil back over itself, burying last years
left over mulch. Bend low while digging
and use your elbow to leverage against your knee to transfer some of the weight
from your lower back.
Stopping every five minutes to arch your back (a reverse of
the digging action) will also keep your back from complaining later.
Now you can add some compost. I like to keep two heaps going side by side
so there’s always a good supply of rich and crumbly organic humus to access
which will be full of worms and bugs large and small. 
Chemical manufacturers will try to tell you that their
special formula is the best but that's just marketing-speak – they just are not
as clever or as comprehensive as a compost heap full of bugs and worms.
Spread as much compost on your newly dug plot as you can – its
difficult to overdose though a layer of about 4-5cms should be sufficient – and
mix it well in with a multi-tined hoe, before a final rake over to remove any
debris and stones.
A watering will help the worms feel more at home after
all that upheaval and then its also good to let it all sit for a few days at
least, allowing some of the larger air pockets to reduce as the ground settles.
A final sprinkling of blood and bone will provide a long
lasting extra supply of nutrition which is best raked in and watered to leave
your veggie bed in perfect shape to plant some new seedlings.
