The photo below is a clear example of one of my mistakes. This occurred several years ago and I only wish I knew where the panel was today and I'd gather up my brushes and fix it. I seem to remember it was shipped to Texas. Frisco, I think.
Tree's are a common subject on sign panels but so are many other objects that need to be grounded. This one has the tree floating. It really needs to a base to be along the bottom. And along the bottom it should have a soft. That would make the whole thing much more realistic.
Joe