Does anyone have any suggestions for how to bill time using GTD? I'm a marketing consultant with 9 clients and am constantly replying to emails from clients and doing small tasks (some are less than 2 minutes) throughout the day. I often don't take the time to write down the time but will get to the end of the day having worked all day but have no billing to show for it. I'm getting busier and busier but it doesn't seem like I'm making any more money.
I bill clients by the hour but only count the actual minutes I work (i.e. I don't 'round up'.) I also submit detailed invoices but feel weird about billing someone 5 minutes and explaining 'answered your email'.