Rule of thumb, as I have known it...
Latin dances, near the center of the floor. Make sure you can be seen 40 feet away from each judge, because closer than 20 feet, the closest judge will actually overlook you.
Standard/smooth, since there is so much progression, middle track of course, but don't cut corners. If you can do something "cool" in the middle, great... but do it well. As long as you are clearly diagonal wall or center, progressing in LOD.
The one thing I know I have to work on is "showmanship." That's the daily mental exercise while I practice this week.