I'm starting to look into doing contract work again, and there's this article that I read some time ago that made an impression on me: How I went from $100-an-hour programming to $X0,000-a-week consulting by Patrick McKenzie (patio11)

I vaguely remember that for contracting, I should prefer charging by the week or month instead of hourly. This is because with an hourly system, the game system is set up such that the person paying is incentivized to micromanage the person being contracted to cut costs. This causes a focus on counting hours instead of focusing on the work that can be done, and I think this also reduces the quality of the work you can do. If I can charge weekly, the quality of my work will improve because it lets me focus on what value I can bring to the table.

However, it's been a while since I've read the article, so I want to refresh myself on the points.

In the article, they say that weekly billing is strictly better than hourly billing because:

• You don't waste effort itemizing the time you spend.
• You can schedule uninterrupted work in weekly blocks to work on units of work.
• You can more clearly connect units of work into to quantifiable business goals.
• You have conversations about negotiating scope instead negotiating price.
• You have better work-life balance, because clients do not feel inclined to just bill more hours in a week.

The author backs up this advice by pointing out that clients want to pay for value that they know makes their business more profitable, and not for time.

There's more information in here about scaling a consulting business, but for now I think that's enough.