Painting BIG

I started a very large painting (large for me anyhow) which is about the size of a door...1mx1.8m approx. This is a detail of it. I was going to take it RAWByron, but had to pull out. Just can't afford the flights at the moment. 

Anyway, I will finish the painting...I will aim for it to be one of my best, and I will put it up for sale at Artfinder. There is something freeing about the start of a BIG painting...it's when it gets to finishing it I run into problems...how to make it sufficiently detailed and not fussy.