Those tiles look good. What did you use?
as you can see on the picture, i use a piece of corrugated paper (a green one this time).
All my buildings are based on this same roofing style where tiles are needed. Cost : nearly nothing
the tiles are design with a simple cutter.
I draw lines with the cutter and a ruler to simulate the tile lines. Don't press on the cutter to cut only the rounded shape of the corrugated paper
simple but efficient, isn't it ?

a sample :
