For languages, I usually write something that generates data, saves it, retrieves it, puts it in sqlite, processes it, reports on it. Boring, but it makes you i

For languages, I usually write something that generates data, saves it, retrieves it, puts it in sqlite, processes it, reports on it. Boring, but it makes you implement some basic data structures, loops, logic, organize code into functions/classes/actors/whatever, deal with i/o and output. It's boring, and takes a day or two, but when I'm done, I usually can code reasonably well in the new language pretty quickly - but mastery of that language can take years.