Thank you all for your responses.
With your help, I have found a solution, which makes me rather happy! Apparently, in the attribute editor of a mesh, you can set the triangulation direction of the quads to left, right or best shape. Using this feature, I just divvy up the mesh into separate parts, set up their triangulation directions, and whoopee -> triangulate. This simply allows me to triangulate entire sections of my terrain into the direction I choose, which gets rid of the nasty artefacts I've been having.
Wondering what artefacts? Here's an example!
I am now one happy artist, so I thank you all for your endeavours.
I'm one step closer to finishing this skiing terrain.