Start with the silhouette.
An alphabet diamond is a diamond shaped as a letter, rather than a letter assembled from many small stones. The outline, internal openings and proportions all influence the design. Not every silhouette or size will be feasible; an inquiry begins that assessment.
Then consider the details.
A custom discussion considers the intended use, dimensions, available material, cutting possibilities and setting requirements. Specifications, grading documentation and commercial terms must be confirmed for the actual diamond. No concept image should be treated as a promise of final appearance.