I think most might say to that, yeah I always do the sills and frames, but most of them will be WFP. I don't know any trad cleaners in my town the cleans the frames, and to be honest I don't do it. I can make more money on glass cleaning than frame cleaning, as most customers see it as an extra, but in truth the PVC can take longer the the glass, and they wont want to pay more than double the price to add it in, so I don't do it.
I would also say be carefull with people, you are out do make money, so dont do things for the sake of it. People will take advantage of you if you do that. I have plenty of people try it on.
I had one customer who I went to and gave her a qoute for the windows and she said could you give the close windows a quick rub over. When I had a look at the floor to ceiling walls of glass right round the corner I told her they would cost more than double what I qouted her for her flat, ohh the last guy just did them, it will only take you two minutes, yeah right pull the other one missus.