[PolemicThoughts]

I switched from a permanent role to freelancing last November, so I'm relatively new to this, but I'd be glad to explain what I do.

I make my skill set clear to my clients. "I can do this, but I'm not familiar with XYZ, so it will take longer than usual." I bill for reading documentation-- just because I'm not writing code, doesn't mean I'm not working. I made my skills clear, and they still decided that they want me to do it, so reading documentation comes with the territory.

I also try to provide an estimate with granularity of half a day (4 hours).

I don't bill for the time spent generating invoices, as that seems hopelessly recursive. I keep notes of what times I worked during the week with a granularity of 10 minutes. All of my invoices include timestamp ranges and a note consisting of 1 to 3 sentences describing what I was doing during that period.

[collyw]

That seems like a fair way to do it.