Early on, I decided to do the soffit for the overhangs (eaves) with plywood, rather than the usual perforated vinyl or aluminum products. Even though it’s hard to beat how easy and convenient those are to install, they can look ordinary and “cheap”, and really don’t match the look I’m going for with the exterior of this house.
My first thought was to just cut holes and use standard vents to cover them, and even went so far as to buy all of the vents. When I did a mock-up, I found that those looked even worse than the vinyl or aluminum. I quickly came up with another plan, and that was to cut evenly spaced slits in the plywood to act as the vents:

The biggest problem was that this didn’t look very good either, since the slits didn’t all line up precisely (despite my use of a straightedge to guide the cuts). Another potential problem was that the slits were only the width of a saw blade, and would eventually get close over from painting the soffit. Also, it looked very plain and I wanted something with a bit more detail.

I had lots of time over the course of the winter to come up with what I think is a much better solution. Individual grills made from solid wood that are fastened in place over holes cut in the plywood soffit:

The construction of these is very simple, strips of spruce cut from well seasoned framing lumber glued and nailed together. I planed and sanded the face of each, then rounded the corners and edges.

Painting these would be a very time consuming job with normal methods, so I came up with a faster way – dip each grill in diluted primer and let the excess drip off. Surprisingly, this worked very well, especially after I got the hang of it:

After the primer had dried overnight, I rolled a coat of paint on the faces and edges and let that dry. I figure the primer alone in the slots should hold up well, since these are very well shelter from the elements.
Spraying is another option, but it’s hard not to make an extra heavy build-up of paint on the face, while trying to coat the slots. Spraying would also take a lot longer; dipping was messy, but is was extremely fast!

To keep insects out, regular fiberglass screen is stapled to the back of each grill. The vents are installed in the soffit with just finish nails. I figured there was not much chance that these will ever be taken down, so no need of using screws. A bead of caulking seals any gap around the vents and helps to make them blend in better:

I must say that I’m very happy with the results and feel the time and effort paid off fully:

As for materials, I used a total of two 2x6x8′ and one 2x4x10′ for the strips, glue and pin nails to put them together. It took roughly a full day to make all twenty-four of these for the whole house.

I made a short video going through the building and installation process: