To achieve a nice smooth effect on chord changes, first find all the main triads on the left hand, and get used to changing them as if you were playing gutar chords. That'll keep you busy for a while!
Then, try 'pedalling' - holding notes over, with the right hand, like this:
Find a note which is either in, or works with, both the chords you are changing, and leave it down across the change. It avoids ay gap between the chords. (C for chords C and F, D for D and G etc).
Then, once the left is 'speaking' again, move the right to a new note for the next change, and so on.
You can also pedal in the left hand. Just leave any common notes pressed in, or even any note you like which achieves a nice drone effect. This is something duets do really well but no other box can manage easily.