my 5 rules
don't wear it unless its actually raining hard (get a windproof)
don't wash it unless its dirty
if you do have to wash it – use nikewash or whatever
dry in tumble dryer/ or iron to reaactivate DWR
test jacket by splashing water on it – if the water doesn't bead up – re-proof
all jackets wear out but they last longer if you do this