I use a spreadsheet, sort of like a checklist in the field, then punch it in at home to do the quote. Its time and materials; and thats the only way to go.
One thing I do when quoting walls is give them the price for the actual wall and put an inside and outside figures on the earthworks/prep work.
If you build your spreadsheet up from all things you missed and screwed up on previous jobs it becomes a very powerful quoting tool.
Regards from Perth, Western Australia
Lady: You Sir are Drunk!
Winston Churchill: Yes Ma'am but you are ugly, and tomorrow I will be Sober.
Sarcasm may be the lowest form of humour....but it sure is fun!