user12972: You had a long day and your batteries are drained. You would like to improve your chess though. How to do this in an appropriate or maybe even restorative way? Should you practice at all or do something else instead? 
I found myself blundering away in games or tactical puzzles and moved away from it to look for better ways. How or what do you guys practice if your mentally exhausted? 
Edit: Thank you for your answers! 

user4418: Yoga.
Failing that watch your favourite TV programme.

user14202: When you are tired but want to study it is probably a good time to watch chess videos. You don't have to be sharp to absorb someone explaining some positional ideas, or get some exposure to theory.
Also, playing through recent GM games just to flag ones you want to look at when you are not tired can be a helpful way of keeping up on things.

12972: <p>You had a long day and your batteries are drained. You would like to improve your chess though. How to do this in an appropriate or maybe even restorative way? Should you practice at all or do something else instead? </p>

<p>I found myself blundering away in games or tactical puzzles and moved away from it to look for better ways. How or what do you guys practice if your mentally exhausted? </p>

<p>Edit: Thank you for your answers! </p>
 4418: <p>Yoga.</p>

<p>Failing that watch your favourite TV programme.</p>
 14202: <p>When you are tired but want to study it is probably a good time to watch chess videos. You don't have to be sharp to absorb someone explaining some positional ideas, or get some exposure to theory.<br>
Also, playing through recent GM games just to flag ones you want to look at when you are not tired can be a helpful way of keeping up on things.</p>
