I'm building a 28' x 15' deck and the framing is just about complete. The composite decking will be laid on a diagonal (45 degrees) but I am not sure how to cut the decking around the 2 x 4 railing posts which will be bolted on the rim joists from the inside. Is there a technique to accomplish this accurately as each deck board is very expensive and I want to minimize waste? Thanks.

Set the deck board in place against the post, and scribe the outline of the post onto the deck board, and cut the post end first. Then set it in place contacting the post, and amrk and cut the other end last.

Thanks Richard. That worked. The key for my understanding was cutting the opposite end last.