Lead by example, ( IMO )
1) I started doing this last year, but when we come up on a slower group of riders, I size them up, give them a little room so i'm not tailgating the heck out of them, and when they let us pass , I wave and signal " THANKS ".... just seems appropriate !
2) when going by a stopped group with a down sled or the hood open , I go by slowly and give them the " thumbs Up " signal , just to see if they need help.
3) when someone is stuck or wrecked or flipped over, we always stop to help pull them out at least to upright their sled.
I do this stuff because I believe in Karma, plus it's just common decency to me. Not to mention it sets a good example for my kids or the other teenagers in our group.
I'm kind of surprised, when I do the 2nd at some of the looks I get. Most sledders will give me the thumbs up back but... some have just gave me the "stink eye" . When that happens , I just chuckle and call them " jackwagons " and proceed onward.