A cuppa along with politeness is more than enough mate.
I can remember doing inspection & test certs for then council properties. The older generation lets say mostly came with a cuppa along biscuits or cake I ended up pitting on weight over 3-4 months the job took. At the other end of the scale youd get the younger generation screaming at their kids, whilst the cat or dog is peeing on the carpet and not even an offer of a glass of water. Mind you I wouldn’t have wanted one anyway. Then there were those who offered you more than you bargained for!
I was never a fan of domestic work, new builds were fine however I spent most of my working life after finnishing my apprenticeship at the Michelin, in mainly the commercial sector.