How to Make Backgrounds for 2D platformer?

So I know using big *ss images as backgrounds isnt very efficient and I one of my smaller games has shows that those big images often don't even load properly.

So what is a good way to go about creating "elaborate" backgrounds for 2 platformers? Say, for the sake of the argument, that I am working on a 6000:2000 Layout Size, obviously, an HD image covering that entire space is way too big. So, do I create smaller Tiles like you would a top-down pixelart game? What if I would want a nice looking mountain with the sun going down, I can't create that with only a dozen tiles. Do I then draw the image as I want it displayed, and then cut it into smaller bits that I then place on my layout?

Fire away guys! Teach me how to make some nice looking 2D backgrounds

As you mentioned, the "cut into smaller bits" part is the way to go.

There is a clear example of that method depicted in that blog article.

Try to reuse as much bits as possible in a creative and pleasing visual way.

alright thanks