Glass microscope slide. The greatest thing ever. Each one has 8 clean, sharp, square edges you can use. They are great for light finish scraping, not heavy scraping (they will break). Use a steel scraper for heavier scraping.
Cutting wood off clean with scrapers, chisels, and planes, will almost eliminate any whiskers before you even start. Sanding mashes down the ends of the grain, which get raised back up when you wet the wood.
It's best to "bone" (burnish, with a piece of antler, smooth steel, whatever. I use a smooth polished antler tip) after the grain is filled with the finish of your choice, but before applying any top coat of varnish.