Your work is great. I've worked on a few applique squares like this.
Is your church stone 1 piece of fabric or are you using small pieces to create the stone look? You can take and outline the stones with the sewing machine or by hand to get the look that you want.
For the tree beside the church, you could do that by hand or machine embroidery (if you can) to achieve a lighter looking tree.
Just a few thoughts.... Feel free to write me if you have any other questions...
Kat