Elegran
It seems we should strip off as soon as we come in from the garden or from a walk in long grass, have a hot shower with plenty of soap, and wash our clothes on a hot wash.
I can vouch for the fact that the shower works. When I had an allotment, I adopted that practice, showering as soon as I got home. Unfortunately now that I grow my veg at home instead, I am in and out of the garden all day long do it is no longer practical.
The advice about washing clothes is interesting, but is different from the advice that I have been following, which said that hanging your clothes up in the sunshine for a while would work, as the resulting dryness would dessicate the mites. It seems to work.
Dispute nine years of severe attacks, I have still never actually spotted one of these blighters!