Dump the hi viz jacket as they will think your a pikey offering to tarmac the drive.
Never say "sorry to bother you" or anythink like that.
The 2 best lines that worked for me when I canvassed up my round was.
Morning ... Do you need a window cleaner ?
or
Morning ... Im THE local window cleaner ... I clean a few in this area and just looking for a few extra customers ... would you like me to add you to my list ??
Both will get a yes or no straight away which is exactly what you want with canvassing for window cleaning.
Usual stuff ... smile ... eye contact ... step away from door ... polo shirt ... no smelling of fAgs or booze ... note book in hand or clipboard.
Dead easy to canvass but numbers game and I canvassed every Saturday and most evenings for 6 weeks anf got just under 100 customers .... then I cheated and bought a round or 3