Shower flow rates are somewhere of the order of 10L/min -- potentially rather more if you're talking about power showers -- so the showers-are-more-efficient-than-baths thing is only really clear cut if you take relatively brief showers. I think some of the comparisons I've seen in the past have pointed to 2 minute showers, which seems pretty rushed, especially if you have hair to wash.

If you have a family, can you share a bath (taking turns)? That's a substantial and fairly easily-achieved saving.

If you've got a garden, adding a gray-water collection system also makes things that little bit less wasteful, at least in the summer (but I suppose that would also work with a shower too...)