How can I improve my overall fluency and the ease at which I am able to speak and understand French?

The greatest advice I could give would be to just immerse yourself, read, listen and speak as much as possible- use every opportunity that arises and search for those which are less visible and will push you! With only 10 minutes every day, you can absorb a treasure chest of vocabulary just from glancing at new articles- whichever the area of interest, or watching videos posted by credible and informative sources, for example le Monde or Fr24.