100%

Most of the time we are operating at what amounts to about 50% of our actual capacity. If we really focus and work hard, we may be able to get up to 80%. But, generally we drift along being "good enough".
We always keep something in reserve. That may be a habit rather than a necessity. Sure, we cannot operate at 100% all the time or we may burn out. But, think about the times when you really focused yourself on the tasks at hand and cranked out something you were really proud of. Or simply a time when you focused properly so that what you accomplished was quality rather than simply "done".
Now imagine doing that more often. What could you do if you simply made it a habit to focus properly and completely on what you are doing? You would have a lot more to be proud of.
If you simply work on the habit of performing at 80% rather than 50% you will in the next few weeks produce better results, enjoy better experiences, and perhaps extract more results from your time than ever before.
That sounds good to me. A little more focus for a much larger reward. Time to put some more life into living...