Dr. Baird's favorite diamond for gross reduction for veneers is a large 66-R XCoarse  
"The Gorilla Bur"  (Pollard Dental). 

The advantages are:

- Faster cutting.

- Smoother surface due to larger contact plane.

- Less whip.  

You may have your favorite.  This size and shape used is a round end taper with a 1 mm tip width, a 82-R.  Or you could use a 83-R with a 1.2 mm tip. (Pollard Dental).

Regardless of your favorite size, do your gross reduction using conservative depth control.

Follow your depth cuts in removing the facial surface.  The sub-gingival and interproximal margins will follow later.

First, a few points on design.

There are three traditional incisal cuts that are still used today.  A straight angle is pictured here.

Forces coming from chewing could fracture the bond.

Imagine a mountain climbers grip.  If you can't wrap your fingers around the grip hold, you could loose your grip.

Your veneers have to wrap around the preparation to hold onto the tooth.

Don't over do the angle.  The thin margins will fracture.

This thin of a margin will not last long before it cracks.

Round the angles so there are no stress angles that can cause cracking.

Use a GB-82 (Pollard) to bevel the margin at a curved 45 degree radius.  This will make your margins easier to see and they will be slightly thicker so therefore, stronger.

Facial has been reduced.  Marginate all margins with a GB-82. (Pollard)

Continue subgingivally after retracting tissue with small gauge suture silk of operators choice. Avoid excessive pressure and chemicals for better post-op tissue response. (The green mark represents retraction silk.)

Order some below.