How do I make my libGDX game resolution/density independent? Is there a way to specify image sizes as "absolute" regardless of the underlying density?

I'm making a very simple kids game; just a bunch of sprites displayed on-screen, and some text for menus (options menu primarily). What I want to know is: how do I make my sprites/fonts resolution independent? (I have wrapped them in my own classes to make things easier.)

Since it's a simple kids game, I don't need to worry about the "playable area" of the game; I want to use as much of the screen space as possible.

What I'm doing right now, which seems super incorrect, is to simply create images suitable for large resolutions, and then scale down (or rarely, up) to fit the screen size. This seems to work okay (in the desktop version), even with linear mapping on my textures, but the smaller resolutions look ugly.

Also, this seems to fly in the face of Android's "device independent pixels" (DPs). Or maybe I'm missing something and libGDX already takes care of this somehow?

What's the best way to tackle this? I found this link; is this a good way of solving the problem?: http://www.dandeliongamestudio.com/2011/09/12/android-fragmentation-density-independent-pixel-dip/

It mentions how to control the images, but it doesn't mention how to specify font/image sizes regardless of density.