As a child, I took organ lessons during which my teacher taught most of the chords by their inversions to minimize the amount of travelling on the keyboard required by the left hand.
For example, A was played A C# E and C was played G C E. To move from A to C, you don't move your thumb, just the other fingers. An advantage of this technique was that I rarely have to look at my fingers.
Now that I'm older, I find myself accompanying groups on the piano more often than on the organ. Since I can't depend on the foot pedals to play the bass line, arpeggio'd chords don't sound right using my current fingering.
I understand I need to learn to play chords with the root note as the lowest note. Unfortunately, 25+ years of developed muscle memory are coming back to bite me and I can't seem to unlearn past patterns even though I've been trying for years.
Other than blind determined practice, can you suggest tricks to help unlearn ingrained habits? Did anyone have to go through a similar process on the guitar, for example?