I found it highly rewarding to learn more about the foundations of classical architecture. It helped me to understand the elements and proportions of buildings I see everyday. There are some high value resources available for free, on YouTube, which cover the basics and can set you up in only a couple of hours.
Calder Loth’s ‘Fundamentals of Classical Architecture’ from the ICAA is a must see in my opinion; it teaches about the basics of classical architecture in such a structured way that you can start using your knowledge to identify certain architectural elements right away.
So get yourself a cup of coffee, put the laptop or tablet on your lap in a comfy chair and educate yourself!
Part 1 of the series:
If you want to apply classical proportions for construction or sketching, the following video is highly helpful: