Had a trawl through the iphone, not the greatest pics but gives you an idea
Using plasticard - one I previously did for a client
Using woodland smooth it - currently mid way through this one, will be back on site in July so will take better shots for you then
mark out the area and track with paving tape
not a great angle but gives you the idea, taken before i painted up the concrete area. As I say ill take more shots of this particular one when im next working on it in July.