For some days of the month, not every day, but likely often, I set a task for me or my friends to be suprised.
For myself that could be the advice to do an extra yoga session that day, or bying myself a great new music cd and a fine bottle of wine to spend with my wife that evening.
For friends that could be a task like: call XY by phone a wish a nice day to have. For people meeting in the street: Just give a smile to each shop assistant you meet that day. Or: Try to make at least 3 people smile that day.

I do not like to overstress myself with that tasks, or do not want to get into a hamster wheel by doing the same tasks the same day of the months, so I plan week by week and this means:

One great moment at planning the tasks and several lucky moments while doing them.

But as a new year´s package, I do some year planning and add 12 tasks, each month one, with some special tasks for the future. And: I´ll be suprised :-)

Hope you get clear with this idea :-)