Hi Visalia,
It might help if you could give a little more info about the style of music you're playing, since the left-hand approach can vary with different styles.
Example: you mentioned bass and chords. If you're thinking of stride-type playing, there are a couple of things that can break up the usual bass-chord back-and-forth motion. However, if you're looking for something like light, pop-piano, there are a few patterns that are commonly used. Then there are boogie-woogie pattern etc., all the way up to the alberti bass used in some classical pieces.
I'm looking at maybe creating some more materials that address LH motion, but right now the closest thing I have to what you might be looking for (something that gives you something to do with the left hand, but that doesn't require reading music) is this:
http://www.betterpiano.com/ppptIt actually involves both hands, but if you listen to the very last example at the bottom, you'll hear how the technique can be "adjusted" to facilitate improvising in the right hand. The article contains notated examples, but you don't have to be able to read them. Instead, you can check out the audio files and written explanations about the notes.
Good luck!
James