I think "competitive" (i.e. solving algorithmic challenges for fun) coding really gives you some insight into how to write code that's short and to the point. The user with the most reputation on LeetCode, for example, consistently posts solutions that are surprisingly short, efficient, and readable.

https://discuss.leetcode.com/user/stefanpochmann

(some random examples)

https://discuss.leetcode.com/topic/18731/7-lines-c-c

https://discuss.leetcode.com/topic/16988/7-lines-3-easy-solu...

https://discuss.leetcode.com/topic/33430/6-lines-o-log-min-m...