I like the window treatments you have. The mini-blinds for the side windows for light control and the slider with no covering. White sheers would also be nice on the slider, but keep the mini on the side windows. I would work on the view from the slider, and put my money there. I'd keep the wooded area pruned and cleared. If you do not need a little patio outside of the slider, I would install a focal point. Here is a photo of a bird bath surrounded by small shrubs. This would be nice to look at outside the slider. You don’t need an elaborate fountain-birdbath, a simple one will be beautiful.

A top treatment like a kick pleat valance would be nice. You could do one for each window, but mount them close enough so that it looked like one treatment. The idea of a birdbath for a focal point is great.

I love your ideas! We've added a trellis with a vining flowering bush along the common ground behind our house (though it doesn't show in the picture). Adding a bird bath would be a nice touch.

I've been looking around at window treatments since I made this post, and I love the idea of having one treatment. The kick pleat valance is nice. I also like the Victory valance with buttons, but my husband doesn't like the pole showing. Can a Victory valance be board mounted?

Victory swags are usually pole mounted. You could look at doing a Classic Empire Valance mounted on a board. It has a similar look to the Victory Valance featuring horns and jabots.