We are planning on copying this look in our mud room. The top photo in this link. I think with old barn wood you just mix and match. I think you'll need to mix your wood together and not put certain types together.

Here is a link that might be useful: Barn wood wall

Let's begin by acknowledging that good design and personal preferences are, well...personal! So what one person may prefer, another person may not. That's what life is all about.

That said, interior finishes are generally seen and experienced from rather close distances, since rooms tend to be relatively small. So lots of different types of siding--patterns, widths, details, etc.--likely may be overwhelmingly busy and distracting.

I would look to have some overall design consistency with what and where the used siding may be applied. I'm one of those that think used siding is wonderful, but not everyone has that opinion. You don't say whether the used siding will be raw, stained or painted, or simply left with some or all of these former finishes.

Thus some careful and thoughtful thinking and designing is really needed, including even recutting, remilling or at least, careful selection, will be needed for a harmonious reuse.

An open basement, even 20X 28, may turn out that the used siding only on one wall may be the best solution. Four walls of used siding may be catastrophic! It's one thing to have a "feature wall" and another thing entirely to overwhelmed by old, used siding everywhere one looks! Only you will know for sure.

Good luck on your project.

I like the idea of one wall. I would really practice the selection and placement. how would you attach them to the wall?

Attachment is easy, but really depends on sizes of lumber. The most secure is to attach with mechanical fasteners, ie, small brads or staples to the studs. If the boards are small and not very thick (less than 3/4"), adhesive might work, but I'd use mechanical fasteners so as to never worry.

If the wood is to be painted, then holes can be spackled and sanded. If wood is to be stained, or left with existing finish (which is a great idea if the existing finish is suitable), then the small holes are left alone. Using small diameter fasteners will create small, virtually invisible holes.

End pieces may need glued biscuit fasteners to keep ends from lifting if they are not possible to fasten to studs.

Good luck with your project.

Most of these boards have never been painted.
My plan is to use 1/2 plywood, or perhaps only 3/8 thick, on the wall and paint it flat black. That will provide a background for any missing knots, splits and boards that do not fit tightly to each other. The boards will be mounted vertically fastened with screws similar to these. The screws will be minimal quantity necessary to do the job but also as many as necessary.
Shorter boards can be used by butting end-to-end at any point as the plywood behind bridges the joint.
That's the plan.

Here is a link that might be useful: screws

Mounting the boards vertically, rather than horizontally, is more challenging on a stud wall. Three-eights thick plywood is enough to nail or screw. Problem with screws is that the heads are large and holes will be visibly distracting, unless filled. And how do you fill them if you plan to leave the boards in their natural state?

So the only reasonable option is to use a nail gun and small finish nails or staples. With plywood backing, you may be able to hold end joints using double nails or staples rather than using biscuit holders and glue (but they would still be more professional!).

Good luck on your project.