I personally have a hard time with timeboxing. I’ve tried numerous ways to timebox, but to-date, about the best I can do is what I call “goalboxing” (I’m trademarking that!). Basically it works like this:
At the beginning of the week, set must-achieve goals that will roughly take half the hours available for the week. In addition to these goals, set goals that would be nice to achieve that fills up the rest of the hours of the week. These are goals, that if achieved, will make an outstanding week all-in-all. And third, set stretch goals. These are generally tackled either at the end of the days of the week, or pile up to be attacked with any left over time at the end of the week.
Communicate the must-achieve goals with the clients and lock them in. Delegate to the team. Get to cracking. Thursday morning, review and decide what to do about any outstanding goals, esp. the “must achieve goals” if they’re not knocked out, yet.
I find that weekly goal setting works far better than daily timeboxing, especially when you’re building a team around you as I do with remote developers and virtual assistants engaged as needed from fiverr.com or upwork.com.