It's a fairly simple (but refined and elegant...) horizontal layout, 'landscape' or 'document' style. One large initial with penwork in two colors, and high rise ascenders and rubrication on the first line.
The first line is penned in here, and the layout lines can be more clearly seen. The sheet under the document is the ductrice for the first line, as pencil lines will often show through red ink. This is possible with Pergementata paper, as well as with very fine parchments.
The sketch of the initial. The lines mark where the red and blue sections of the varigated initial will be.
The blue sections of the initial added. I usually lay down the blue first, as it has better covering power over the pencil lines. Slight miscalculation, the blue on the bowl of the 'R' should have been on the inside, not the out. It's not a huge issue, but it could have been more interesting (as well as more consistent with the rest of the initial) to have had it on the outside.
Red sections of the initial added. I don't generally draw out the whitespace in between the sections, just kind of paint carefully around it. I also let the blue dry thoroughly before painting, and erased the pencil lines, as they have a tendency to show through the red paint unless you lay the paint down very thick.
Two different shots (I couldn't decide which was the best) of the initial with first run of red ink penwork. The pattern on sees is that red penwork goes around the blue section of the letter, and blue penwork around the red sections (hence my previous comment about how it would have been more interesting if I'd got the blue in the right place).
Here with the blue penwork added, both as highlights to the red and as base work along the red portions of the letter.
Another run with the red ink to highlight the blue penwork in counterpoint to the red, and the initial is complete.
Essentially the same thing, minus a few stages, for the initial on the King's Champion. I have omitted the pics of the layout and calligraphy stages, as they are basically the same.