I want to describe first with words and then will add photos tonight.
On the side you want to remove a flake from must be prepared in 4 stages
1. Make sure the opposite edge does not contain mass that will slow the travel of your flake (remove a small flake to relieve mass pressure and help terminate flake)
2. Take very small pressure flakes to improve convexity.
3. Create two very small break flakes to releive pressure build up on each side of the platform you are going to hit
4. abraid the surface to be hit to promote convexity
On the platform side prepare in the following manor.
1. Pressure flake in 90 degree angle downward from the edge. I find that this will create the best platform for antler.
2. A break flake (very small) on this side toward the bottom, outward will help prevent a colapase resulting in a small double fracture. These small fractures dont seem imporant to avoid if you want a 6:1 but achieving an 8:1 will be difficult because they start acummulating. To remove them you have to build stronger platforms resulting in deeper flake scares and increased convexity and that leaves you chasing rabbits toward a thick ratio and scratching your head and screaming why oh why is this so hard.