Just a few minor observations on this very sad occasion ...
1/ Quadrantial flying in VFR/VMC if at all possible. (UK). (Won't stop speed difference / overtaking accidents though). Take a friend - doubles the lookout.
2/ Flying "Just Off" the levels "everyone else" will be using - +/-100 ft - If people can fly this accurately (!)
3/ The gliding and microlight folks - and plenty of the GA community too - can't come up with "only" £ 5 K for new transponder kit. You can buy an aeroplane (or a large part of one) for that !.
4/ To (glass) glider pilots - take a roll of aluminium foil up with you - it will really increase your radar return !. (I was told this by my old PPL instructor - Possibly an old wive's tale - any ATCOs know ?).
5/ Why can't we expect good LARS coverage ?. Where does all that duty on the AVGAS go ?.
D129