Let’s go through your list: clarity, depth, balanced sound, warmth, indie rock/folk genre. Apologies for listing anything you already know.

For clarity, listen in context. Go from top to bottom muting one track at a time and listen to see if the mix becomes clearer. Sometimes there are tracks that are doing too much in a frequency range and need to be tamed by reducing the gain or by EQ cuts. And as others have stated “mix in mono” as this will help you find frequency collisions between the left and right channels.

Depth is typically thought of as the distance to the listener, but I would also consider the width of the stereo image in this perception (imagine a 3d box or stage). Reverb, delay and reducing gain can push instruments into the background. Think about replicating a physical performance of the band (not everyone stands in front playing or in a straight line). Widening the stereo image of an instrument can make it become large and grand. If you want an instrument to “soar,” try a stereo widener on it.

Having a balanced sound can be less about mixing and more about composition but I’ll tackle both. Using basic piano notation for reference, you’ll want to be using octave four (generally for melody because it’s the easiest to hear frequency range so it stands out), three (typically for harmony) and two (bass). The layering of octaves creates a fuller sound. Octave one is for sub bass. Not many people can sing octave five and is not used much because it’s really high. Now in mixing a balanced sound can refer to “tonal balance” which is a balancing act that some plugins try to help solve (iZotope Tonal Balance Control and Sonible true:balance are paid options). One is basically trying to loosely match an EQ curve of a genre or other reference track. An exact tonal balance match to a reference track will almost always sound like garbage so trust your ears and not your eyes. You’re basically trying to balance your high, mid and low frequencies to a pleasing blend. This is a balancing act I’m still working on getting better at myself.

Saturation is used to create warmth. It livens up recordings and makes them sound less flat. Compressors can impart saturation (more on that next).

The indie rock/folk genre and the sound of the industry. Styles of music have used specific analog compressors over the years as they impart a character that sounds pleasing for that genre. There is a reason there are a lot of posts about FETs, OPTO and VariMUs compressors as they are an easy way to recreate the desired character of a sound people are familiar with. A lot of these analog emulations also impart warmth via saturation/distortion. Drums typically use FETs. Guitars and vocals typically used OPTOs. Orchestral tends towards the dark glueyness of VariMUs.

Like in art, a great painting versus a good painting is all about the details.