To Don,
In my limited experience with flat tiles on sloped roofs the rules and techniques are basically the same, although in some details of roof tile installation Portland cement mortar is used for filling, esp at rake edges.
Nice picture with the lead step and counter flashings. Good work. Covering the roof planes is straightforward and easy to learn and do well. Using proper techniques and materials for flashing edges, intersectons, valleys etc is where excellence in attention to detail is required and what will insure a good effective job well done. More than half of our roof work over 39 yrs is replacement and or repair of faulty flashing work. Could have, should have been done right the first time.
I enjoy seeing your creative work on your blog. Do you still need a smart farm dog? one of my Aussies? I have 3 pups available.

Shine on!