Personally, aside from a cat or dog I have had excellent luck with a trap called "The Better Mousetrap". It has a bigger trip on it and baited with peanut butter works like a charm. I live in the country and every now and again a mouse gets past the cats and dogs outside and finds its way into my house. Since we cannot have a cat inside due to my spouse's allergies, a mousetrap is the only choice.
As for building one, I have never tried. I like the one I mentioned as it does the job and death is instantaneous so the little rodents don't suffer.