Here's what I do. I learn chess and play chess. I recommend you read books to improve your game and make studies out of them. Here is an example of one of my studies on Lichess.com. I play the moves they play in the book but I would also put in some of the notes, mistakes, and interesting ideas that are mentioned as well. Of course, you don't have to do everything the book mentions but the main ideas and anything helpful.
Here is a link to 87 quality chess books to study from all for free. Scroll down and you will find download options and I like to download pdfs and send them to my iPAD and copy to books.
The books help and when you play, you should try to implement these ideas. If someone plays an unusual move that the book doesn't cover or haven't gotten to, finish the game and look over the move with an engine and see what you should do against it. This helped me improve a lot and hope you get something out of this.
Nice link!! I didn't know so many could be found for free.
You should not be finishing games with more than 20 of your 30 minutes of the clock then, lol. Unless it was an easy win. Make sure you know the value of the pieces and avoid letting your opponent get ahead in points. Double check your moves to make sure they can't take your pieces for free.