Running an early line into the buoy is fine, but no matter how early you are, straight-lining into a turn will force a sudden change of direction and rapid loss of speed at the ball. Skiing outward from the wakes to the widest point possible will ensure the sort of fast, flowing that allows you to set and maintain angle, and leave you feeling light on the line. Skiing wider is simple. You just need to delay your separation from the handle for as long as possible.
As you separate from the handle during your edge change, your anchor point raises, meaning, the handle gets higher in relation to your body. As the pull transfers from your entire body, to your shoulders alone, you will tip in towards the boat. This is when you will begin to run parallel with the course, killing your outward direction. The later this happens, the wider you will be.
As you leave the wakes, ignore the turn and the buoy, concentrating instead on maintaining your connected position (hips close to your handle, arms close to your sides) all the way to the buoy line. This will keep the pull low, through your entire body, as you change edges, ensuring you are not tipped inside your desired path.
Premature separation (it even sounds bad) is usually caused by either cutting too hard into the wakes, or by simply ‘preparing’ for the turn too early. Allow your turn to be the simple result of proper outbound direction through delayed separation.