Its now getting too late in the year to apply roundup etc, as most of
the annual weeds have already set seed.

So remember the old adage 'one years seeds, seven years weeds'

There is no getting round the problem quickly.

I personally would still apply roundup now to get the perenial weeds.
Strim the remaining brash down with a metal cutter on a petrol
strimmer or use a hand sythe. Then burn or cover the remaining brash
with carpets or pvc sheeting. Open up the ground again in spring to
allow the seeds to germinate, then hit them again with roundup when
they are nice and tender.

If you plan not to use the area for a year, instead of using roundup
in the spring, apply something like pathclear or sodium chlorate to
the ground just before the seeds start to germinate. This should last
for nearly a year.

Professionally I would never rotovate or even rotavate the ground, as
this keeps bringing seeds back up to the surface, and also chops up
couch grass, ground elder, and bindweed. Keep the seeds buried.

I have seen pro lawn layers rotovate ground up, with elder in it,
reflatten it, and then lay the turf. Only to find the lawn covered and
I mean covered with ground elder the following year.

Check out http://www.gb-online.co.uk/gardening...lery/index.htm for
typical examples