This step will only cover the construction of the fret board itself, and the inlays. I'll explain putting the frets in in a later one.

Before starting my fret board, I bought some Fender standard fret wire, 24 pre-cut frets cost me the equivalent of about US$10 or so. I would have preferred a cheaper roll of wire, but had nowhere near me to buy it in that form.

I started with a thin pine offcut about 60mm long, 7mm thick and 45 mm wide. I recommend using wood wider than this, though, as it eliminates the need for binding or in my case, wooden "wings" to make it wider.

I used wood planes on the sides of my fret board to taper it slightly towards one end, so that my 'wings' would go all the way to the end, then 220 grit to 800 grit sandpaper for a few hours, to give the top surface of the wood a radius. If you're luckier than me and do not have to make additions to your initial piece of wood, you will still need to taper it to fit flush with the neck. If you're not sure what the radius should look like, look for guitar fret board radius cross-sections online. They vary from instrument to instrument, so choose a radius that you think will suit your style of playing. There should be no bumps or dips in the surface when you look along the top and hold it as shown in pictures 3,4 and 5. The wood is shiny in these pictures purely from the fine sandpaper, there is no oil or varnish on it.

I then cut it to the correct length, in my guitar's case that was 508mm.

Next up, I used two pieces of wood, about 8x8mm square in cross section and 700mm long. I cut them to the same length as the main part of the fret board and used wood planes and sandpaper to taper them at one end, so that they would fit approximately flush with the edges of the neck. I then glued and clamped these wood strips to the sides of the main part of the fret board, using four clamps and a couple rubber bands. Once this glue was dry (about 8 hours later) I added another part, cut from the same pieces of wood, shown in the picture directly after the one showing the clamping, at the wider part of the fret board. The ends of this piece were then sanded down to be flush with the outside wood strips. I didn't worry about clamping it, but I did leave it for a few hours to dry properly before proceeding.

I sanded and planed the strips to all be flush on the surface and underside with the wood, and ensured that the radius remained uniform on both the main piece of wood and the outside strips.

Then, I added some paint. I masked off the main piece of wood, and painted the three parts I had added. I took the masking tape off while the paint was wet, otherwise it would have likely been messed up when I peeled the tape off. I painted over the paint with another layer, just to cover up any patches where it was too thin.

Once the paint was dry, I made cuts in the wood in which to insert my fret marker "inlays". I didn't have any materials suitable for making convincing inlays of a colour I liked, so I cut shapes out of the fret board about 1-2mm deep and filled them with red paint. Before I could do this, I had to know where the markers needed to be. I calculated where my frets would be using this online fret calculator: https://www.stewmac.com/FretCalculator

My scale length was not absolutely certain at this point, but as long as you are within 3mm above or below the final position, your markers won't look very out of place. The frets need to be absolutely precise later on, but the markers don't have to be perfect for the guitar to function. I marked only very lightly in pencil where the frets would be and used a plastic stencil I made to assist in making all the markers the same. I centered the stencil for each fret that needed a marker and made a cut for the outline of the shape, then I removed the stencil, cut the outlines a bit deeper, then chiseled the diamond shapes out using the same craft knife.

Look up standard fret marker locations if you're not sure where the markers should be.

I then filled these shapes with paint, but to ensure that the paint dried faster and evenly through each marker, I painted in layers and only once each layer was dry, I would paint the next one over it. Try to keep your painting neat, but you can remove excess paint a little later.

Once all the cutouts have been filled with paint and are flush with the wood surface, Use fine sandpaper to remove the excess that is on top of the wood where it shouldn't be. The last few pictures show how I did this and how it worked out pretty well for me.

When I was happy with the surface of my fret board, I varnished it. I didn't use a paintbrush, I only wanted a very thin layer of varnish that would protect the wood by seeping into it very slightly, and not being thick enough to make it permanently glossy as this would interfere with playing and look awful after some time playing the guitar. I used 2 ply toilet paper (because it holds together well and doesn't leave dust) to apply some varnish to the fret board, then wiped it "off" again. It's impossible to really wipe varnish off, so all this does is removes most of the surface varnish and lets only a small amount stay behind, which will be flatter and more practical for this application. This must be done quickly though, to avoid any ugly smears or bubbles in the texture. Leave the fret board somewhere where it's unlikely to get dust, pollen or hair on it while it dries.

After a day or more, when the varnish is dry, inspect the fret board for any areas that may have defects, and try to fix those at this point. For example if there is a hair stuck in the surface, remove it and if a noticeable outline remains, use some varnish on your finger to lightly patch the area up and smooth it off, and wait again for that to dry. Patience is important with varnish, as I've learned the hard way more than once.

Once the fret board was complete, I marked on the body where I would need to cut out a place for the wide end of the fret board to fit. There is no picture of me making this cut, but you can see the difference in the next step's pictures.