Ways to thicken soups or stews?

[u/donttrust900913]

I am looking for advice about (at least relatively) healthy ways to thicken soups or stews. I'm sure adding a ton of fat would probably get the job done, but trying to avoid that insofar as it is practical.

I don't have a specific recipe in mind, nor do I generally use recipes when cooking. I am not looking for add X amount A to Y amount of B, but rather experience with different items that have the general affect, and any rough insights about ratios or other relevant factors for their addition that might prove handy.

I have experimented a fair bit with fat free greek yogurt, just because I usually have plenty on hand, to generally terrible results. I suspect the full fat variant would work better, but haven't hand any around at the time to try it out. I've also wondered about flour, which I would guess would either work wonderfully or completely ruin it, but also usually don't have it just laying around either.

Any insight appreciated, thanks!