Step 1: Gather your ingredients
3/4 Cups Flour (see below)
~3/4 tsp salt (or to taste)
~1 tbsp water (depending on flour and humidity)
In Japan, we do not have all-purpose flour, only low gluten and high gluten flours, which we have to mix. If you do have easy access to these flours, you should mix about 1 part low gluten to 2 parts high gluten. Otherwise, just use all-purpose flour. It's not vital to the noodles.
This dough doubles or even quadruples very well, although the dough becomes harder to knead.