London: the first 24 hours

I woke up in Balham on Sunday morning, post house-party. Managed to stay plastic-free (and sober) for the party, which went on for some people 'till the sun rose. However, I realised that I haven't really thought about how I can apply 'no new plastic' to things from other people. For example, I (gladly) accepted a cup of tea this morning - probably the tea bags originally were in plastic wrapping, and certainly the milk was from a plastic bottle. I'm trying to eliminate plastic from my life but certainly not my friends, so I think this is OK. But it might be easy to over-extend this 'exemption' if not clarified properly. I think a cup of tea at someone's house is acceptable, but if I'm offered a biscuit wrapped in plastic, the answer must be 'no'. But it is less clear cut if something has obviously been in plastic, or might have been... I don't wish to be routing through bins to see if an apple came in a plastic bag. Hmm. I shall have to think about this.

Anyway, post-party (and clearing up with plastic bags...) I left for the train station via Waitrose, Sainsburys and M&S to look for some breakfast/lunch. Loose fruit + carrots from Waitrose, along with a muffin (in a paper bag). M&S was the only place for a sandwich - they package them in card with the window made from cornstarch (or equivalent). [My plastic ban only extends to petroleum based plastics, not bio-degradable cornstarch (not to be confused with evil degradable plastic).]

Many delayed trains later I arrived home to be greeted by a pile of letters with plastic address windows. Anyone got ideas on how to eliminate these? I already get most bills online only...