A friend of mine was telling me about this exact issue; they could easily learn to write websites (with a preference for backend), but they ran into a wall when trying to make the website look good. I studied graphic design for 4 years (and it did not go in depth), so for me, this revelation was surprising – I would have thought people are aware it’s a different skillset! But as I searched, there really aren’t as many resources for web developers that want to learn the basics of web design. As was already mentioned, the minimalistic design is often the hardest to pull off… but that’s (with its popularity, too) all the more reason I would have thought there would be more advice available!
Since this topic is interesting for you, I’d like to point out a few areas we focused on in the beginning that you might want to look into (if you didn’t yet):
(1) composition – rule of thirds, proportions, use of empty space (space = room to breathe, people tend to make things quite cramped), …
(2) contrast – not just for readability, but to bring focus to important parts (contrast can be in light x dark, warm x cool colours, bright and desaturated etc., but also in size, plain background x details, …),
(3) design that fits the theme – i.e. you can go beyond “handwritten font for a craft website”, you can use associations people have with the field in general, with colours, with shapes,… (like you’d expect, say, something dynamic and luxurious on a website for car racing, but that would be inappropriate for a funeral service where you’d go with more serious feel),
(4) less is often more (simple layout, limited colour palette, 1-2 fonts per page)
I hope something in that wall of text will be helpful for you.
But it really is good to see someone coming from non-artistic/designer background interested in this topic!