Funerals for the Fallen.

Something I put in my house rule doc but never actually made a post about:
Funerals.

In essence:
Take a dead character's remains to a safe place with a church (or cultural equivalent) and you can buy their experience points on a 1:1 silver-for-exp basis.

This represents money spent on funeral rites and memorials and bar tabs and other things purchased in their memory. The player spending the money does, of course, say what they're spending it on.
It basically pans out as a limited but consequence-free version of Carousing.
Bear in mind I'm on the silver standard here, if you use the gold standard you'll want to make that gold-for-exp.

After some testing it's been a remarkably good little rule!

It encourages the retrieval of your buddy's corpse from whatever horrific death consumed them, accomplishing my favourite little trick of merging the intentions of player and character together.
"We've got to go back for Larry's body! We've been through too much together to let him rot in this hellhole!" and "We've got to go back for Larry's body! He's a big sack of easy exp!" end up resulting in very similar behaviours.
You get the same sort of thing with Level Drain. "Holy shit, A GHOST!" and "Holy shit, LEVEL DRAIN!" both induce the same mixture of fight and flight. The trick is to make sure the player knows the mechanics at the time.

Some other impacts:

It's much more worthwhile to take higher level characters' corpses with you.
Nobody really cares about Jimmy Newguy the Level 1 Thief, so leaving his corpse to be eaten by Carrion Crawlers isn't a big deal.

But Big Bill Ballswinger the level 5 Fighter? He's been with the party for a year! He's seen more newbies get eaten than I've had hot rations and saved my life on fifteen separate occasions! He needs a proper burial with a parade and a statue and everything!

On that note, higher level characters "deserve" more lavish send-offs than their lower level brethren. Nobody's going to do much for a level 2 Thief, but that seventh level Cleric is getting a whole damn church raised in his honour.

Getting a corpse back out of the dungeon is interesting logistically, especially if you didn't manage to kill the thing that killed them. I had players venture, against their better judgement, into a spider lair to retrieve a corpse. A corpse! Usually I only see rescue missions to retrieve still-living hostages!

It acts as a way to let long-running players start their next character at a higher level.
In my game, you can put money in the bank. This is for safe keeping and a wild 2% p.a. interest rate, but mainly because you can pass the money (less a 10% death tax) on to your successor.
This means a new character can swagger in, burn all his money on buying up his long lost twin brother's exp, and be back on his feet minus a huge chunk of his inherited fortune.
And getting rid of that fortune is, perhaps, the real point.