Sock Fight
Something that my brother and I have done many times as kids are sock fights. And I'm not talking about just throwing socks around but using them as whips. I would consider it "safe" but I recall some bruises.
There was a particular way my mom would fold socks which seems typical. You fold the socks in thirds then take one of the sock openings and stretch it so it covers the whole bundle into a ball. Here are some step-by-step pics if don't understand what I mean.
You can now throw them fine but they are too soft. But now if you then grab the part you stretched over and swing the sock around it will end up having an inside-out sock with the other one inside in the form of a tight ball. Now you have a combo whip/club which you can swing pretty hard. Tip: If you can manage to hit your opponents sock in flight it will tend to spirl around each other and if you hold on tight and time it right you can yank the sock right out of his hand. If they both hold on tight it will unravel very fast and hit both of yourselves in the face!
We stretched out lots of socks as kids but we had endless supplies on xmas from grandma