The #1 best "Blender tip" (that also applies to computer graphics in general), is that by default it is
horribly incorrect with its treatment of colour spaces and especially gamma/tonemapping.
Rather than me clumsily explaining with text how to get this right and have your artwork "pop" with very little effort, watch this video titled "The Secret Ingredient to Photorealism": https://www.youtube.com/watch?v=m9AT7H4GGrA
Combine that with physically correct materials and rendering, and you could literally "sketch" a handful of grey boxes with a single area light and have it nearly pop out of the screen with uncanny realism!
The #2 tip is that chances are that you're probably working with a cheap LCD monitor. Even for $600-$1000 you can get a very decent monitor with DCI-P3 or AdodeRGB wide gamut support and more accurate colour. That helps to produce content that is consistent and correct. That, or invest in a calibrator and set up your operating system colour management with the ICC profile of your panel. Without this, images you grab from Chrome or Firefox will shift in hue and/or brightness when you import them into image editing software. Test your browser with this site: https://cameratico.com/tools/web-browser-color-management-te...
The #3 tip is that you can make much better colour choices working in a perceptual space. The colour pickers in most software use trivial RGB 0..255 ranges mapped to a rectangle. This is garbage, criminally lazy, clownshoes programming. Yet, everybody does it, resulting in these "curtains of colour" controls: https://www.google.com/search?q=colors+picker+control&tbm=is...
You shouldn't be seeing those vertical streaks! The transitions should be smooth and even. An excellent space to use for picking colours or creating gradients is Oklab: https://bottosson.github.io/posts/oklab/
Notice how beautiful it looks compared to the other spaces, which are horribly uneven looking?
Even just these tips can make someone like me, a non-artist, produce beautiful images, web pages, or 3D models.
Art isn't magic, it's a technical skill and you can learn it!