While I still think my "Draw the rest of the owl" joke is the best thing I've ever done, realistically you should look at adding environments more like serving to aid the story you're telling alongside the character and what kind of world they live in.

Like look at it more like an order of operations:
- The focal point of the piece is the character, so the background is secondary to serve as a stage for them to be on
- Therefore, the background should include elements that could also frame the character in place to stand out.

Like I do the "add the box around the character" method because I've drawn so many backgrounds I can do it in the reverse order if I wanted to, where I draw the character first before the background. Starting out, strongly recommend you do both at the same time.

One issue I find with people starting with background is they've made the background the main focus, but the characters are placed in kind of weird positions to accommodate for that and it ends up making the visual storytelling a little stiff.

Throw in the need to perspective, and the piece ends up not being as naturally composed as it could be.
Strongly recommend doing film studies to study cinematography and placement of people to direct the eye for scenes.

The reason I say doing both the character and the bg at the same time is important is because characters are just another part of backgrounds, really. Like if you're already drawing 10 million objects in a scene, characters are just one part of them.

Equally important is the fact that characters are your scale measurement to the believability of the scene. How tall are your characters in relation to everything else? Are they considered tall or short for that world you've created? If you notice those anomalies, you can fix em.

In summary, when I say "Draw the rest of the owl" I mean you should consider the focus of your piece and make the thing catered to selling that focus so people know what your work's about when they see it.
Then you just do it again for the next piece -w-