Plugging holes is a barrier everyone who gets into woodworking has to cross but it’s funny how large a hurdle it can be for such a small detail.
I think it starts with the realization that an exposed screw may not look good. Probably the first attempt to fix this includes trying plastic wood or some similar prosthetic beige putty that looks like no wood in existence.
Perhaps you try purchasing those hideous wooden mushroom buttons you see on low rent pine furniture until you realize it’s like gluing speed bumps all over your work.
Next up might be trying to glue sections of dowel into the screw oles if you can find ones that happen to fit. If not, apply copious amounts of glue and sawdust.
Eventually you may discover that plug cutters exist. This is a big purchase for the new woodworker. You may have to invest ten to twenty bucks into this wildcat venture. Once the prospective sticker shock passes you are faced with a few options.
There are three varieties of plug cutter that I have come across.
The first is basically a cylindrical cutter with a large escapement opening on one side. It will produce plugs of any depth up to the cutters limitation, usually a bout 1-1/4”. If your stock is thinner than the opening you can bore straight through and have the plugs pop out automatically as you engage the next plug in the cutting operation. They also automatically fly off into the nether regions of the workshop, a portion of them never to be seen again.
The downside of these cutters is that they produce a square edged plug which can be hard to start into a hole if it is tight. The upside is that they come a wide variety of sizes, up to ones in multiple-inch diameters and that can be found with carbide cutters as well.
The second and third are generally made with four flutes and look identical but with one critical detail.
One type produces a tapered plug and one produces a parallel sided plug. For boat building we want the latter. Both these cutters are designed so that if you bottom them out in the wood, you get a very convenient beveled edge at the end of the plug which is exactly what we want for starting the plug in the hole.
Of course the proper countersinks should be used with those plugs:
Note to Canadians: Lee Valley no longer seems to carry the four fluted straight plug cutters. I have purchased from the US source listed above many times.