Whatever is growing in your area already will do well. it look wonderful with all the trees! If you want specifics on native plants and trees, I would check the library or local DNR or university for information. Most nurseries can help with that too. The first thing I noticed though was that your neighbors have no windows on one whole side of their house. I can't imagine why. it seems awful not to have one window. Is the lower part a garage? even then..eeww :) The other consideration for what you plant will be the soil content, particularly if you want to plant flowers or vegetables.

I have gone to a few nurseries but they aren't very knowledgeable. I'll be glad when we find our go-to nursery! We have a tone of old growth behind our house which you can see a bit of in the last picture. I am careful about cutting in out too much because I want to create a few "secret" sitting areas in the forest. As for my neighbors, you are correct, no windows on one side of their house! I wouldn't like that, especially because there is no cross-ventilation. Anyway, we have ton of work to do but I do not want a long line of thin shrubs! I want a lush, layered, natural looking border.

that's too bad about the nurseries. I would still check the library for resources and if there is a university as well. Usually they are really helpful. I completely understand about wanting to create private spaces in your forest. I think it's wonderful!
I would find out what kinds of pines grow best in your area, how tall and full they become and what sorts of wildlife they attract.

here are some pictures I found in library books and took pictures of :)

Black pine are interesting and can be cut to resemble a large shrub. There are many, many tree options that are full but I always feel more comfortable when I can discuss my options before committing. We are going to try another nursery this weekend. Hopefully it will be the one!

Try staggering hollies and leyland evergreens. The hollies will give you 4 seasons of interest.

Do you have access to a county extension office? Or check and see if there is a master gardner's club around.