Some very practical actions you can try. I’ve used various of them to especially extend the use of my CPU and motherboard for a few extra years.
One I could add though, although it is not cheap, is also considering upgrading for GPU card. Buy one that should be compatible with your next motherboard upgrade.
See https://www.howtogeek.com/887938/inexpensive-ways-to-breathe-new-life-into-an-old-pc/