I have noticed that trying to bill at higher rates has been becoming more difficult and if I don't work a full 8 hours it appears that I am slacking off. The vast majority of software engineers do not do 8 hours of actual work, even including meetings.
However, I sometimes notice other contractors billing a full 40-hour work week and clients not batting an eye.
Am I being too honest, and should I continue billing for the fifteen minutes I go off reading HN, having lunch, or any other short break?
Edit: I guess what I meant to say, is lowering my rate by around 25%, but also being less picky on what I should bill so that I can earn the same amount, acceptable?
As far as your rate, I always bill as high as I can without pushback. Where is that level? You'll know when your rate is too high. I kept increasing my rate with contracts until clients started to grumble a bit. Then I backed it off 10% and haven't had a problem since. Note this means I am getting paid 30% more than where I originally started. Wouldn't have known that if I didn't attempt to max out my rate.
In the end it's just business. You either make a client happy or you don't. As a business your goal is to maximize your profits without much pushback. That will just take some time and energy to find out what the market will bear.