We have three separate paper delivery persons, mornings, evenings and weekends, so we drop off a tip at the shop to be shared between them.
Bin men i tip when I see them.
Don't have a milkman - but used to tip him when we did - I think it;s easy to take for grantedf our deloveries in all weathers - and recently it has been all weathers - and the people are often schoolies or students, so it's nice to show the Christmas spirit.
I dont think the binmen expect to be tipped mark, I seriously doubt they are going to start messing around to get even with the 98% of residents who dont tip. not to mention they would be reported to the council if they failed to carry out their jobs properly, that is what council tax pays for.