What have you been using for time blocking?

Now that I left my full-time job for consulting, I have much more control over my time and I wanna try not mindlessly wasting it by using some time-blocking techniques.
The natural tool for that would be Google Calendar, but I want to expand that horizon a bit and see what's out there. So far, I've tried Plan (getplan.co) and Doist (doist.com) and haven't like either experiences.

Have you been timeblocking? If yes, what tool have you been using?