U. lividia equal parts peat and silica sand. high light levels, moderate humidity. I use the tray method, doesn't need that much watering. flowering nicely!
U. sandersonii seem to do very well in very high light in a variety of soils, (pure peat, equal parts sand and peat, etc). Mine seem to do best when planted with Drosera. No flooding, just the tray method.
hope this helps,
Homer