Just like you did with placing a rosemary branch at the 12, 3, 6, and 9, so too place a single skewer at the 1:30, 4:30, 7:30, and the 10:30. Then, fill in from there based on how many skewers you assembled and what lays best where.
Once the skewers have all been placed, go back in and fill in the gaps and empty spaces with grapes, nuts, individual chunks of cheese, halved fresh figs, pieces of chocolate or cookies or petit fours...whatever makes sense.
It's also at this point that I begin to create layers of meat and cheese and crackers and fruits on the outside of the wreath. The outside of the wreath area is a great space and a great way to ensure all of what you purchased makes it onto a surface from which to serve.