Cooking

You can thin out some sauces with a neutral oil, like canola or sunflower oil. You can mix some sauces into mayonnaise for an aioli. You can use or make sauces that are less hot or less salty.

Depends on the sauce, but one trick is to put a little sour cream in it. Do a taste test before you commit.

i add water in this case; however, if water will make it a but too thin then you can add a water+corn starch mix to keep it thick.

edit: tbh, usually my "water" is water will some chicken or beef bouillon in there

I think you might be a bit confused.

Soy Sauce et al are less "sauce" and more "condiments". They are concentrated flavors that you add during cooking (often to a sauce) or, in small quantities, post-serving.

So my suggestion? Actually make a sauce out of it. Butter and hot sauce is pretty much one of the greatest things to ever exist (it is also the basis for most hot wings) as the fat in the butter really brings out all the flavors in the hot sauce. Soy sauce is often mixed with alcohol (shaoxing wine wine or cooking sake, depending on what flavor of East Asian you are) for similar reasons. Just make sure to boil/burn off most of the actual alcohol content.

But a general rule of thumb is that most "sauce" condiments are very acidic and high in salt and umami/savoriness. So... you can't go TOO wrong with butter or sour cream.

Have you made many sauces from scratch? Certainly a difference between sauces intended as sauce (enchilada sauce) VS those that are condiments (hot sauce). In those examples the line is fuzzy and water is a factor but not the only one.

I suppose you could try adding water to soy sauce but I doubt that would result in a satisfying sauce. I would make another sauce and add soy sauce, hot sauce, mustard, or other condiments to it for flavor but at that point you aren't really making them less potent because you are actually just making a new recipe with the condiments as an ingredient.

I almost never make sauce from scratch.

You know that brown stuff that's stuck to the pan after you sear meat or stir fry meat?

That's called fond.

Add a little water, heat and stir to dissolve the fond, and add a little pre-dissolved cornstarch,i.e. a slurry, to thicken the boiling broth to make gravy.

It usually tastes just fine as is, but you can add spices, wine, sugar, salt or whatever.

A sauce will usually be a liquid with a thickener added. Chicken broth plus flour would give you gravy like for roasted chicken. Chicken broth plus corn starch would give the same flavor with a different texture, like something from Chinese take out. For a thick weak soy sauce, you could mix the amount of soy sauce you want for flavor with the amount of water you want for volume. Mix in some corn starch and heat it up. I don't know how good that would be, but I think it would get you what you are looking for, and you can experiment from that point.

fina'denne is great for a saucy condiment, 1 part soy, 1 part vinegar, then a white onion (as much as you can fit imo) a hot pepper (i use thai chili but any work) and optionally some cherry tomatoes. you end up with a balaced sauce but also some pickled vegetables that hold the sauce and keep it wet but not over wet. might not be exactly what you're looking for but it's delicious. in general you want to cut the strong flavors with other strong complimentary flavors.

So I know when I am makiing stir fries if I want lots of sauce I either add lots of different ingredients to build flavors. For example last night I had a sauce with Gochujang, Soy Sauce, Black Vinegar, Roasted sesame seeds oil, chili oil, chili garlic sauce. Each of which was in a smaller quantity but created a spicy and umami flavor that overall covered anything. So try to make multiple flavors together (which is traditional any way). I do love strong flavors so that might not work for you. If that doesn't work the water + corn starch slurry is a good method to make a sauce thick without adding much flavor.

Tomatoes are the base for most mexican style sauces so add more tomatoes. You can make your own or just use the most mild salsa you can find as a base.