I like skating a board until I am happy and done, without modifications or trying to extend the life, usually passing it on to someone else, who might in turn pass it on to someone else again, if it is still in one piece, or come back to go to someone else to do some art thing with or put on the wall on occasion too.
The two things I have seen people do, both of which have been mentioned at some point in other threads or here, which works and is good if you are keen.
Epoxy / glue or something just on the end of the tail, especially used by some guys I know who skate Powell flight boards to keep it a bit more fresh, seeing as most of those guys never break boards anyway, but they like the flight boards for whatever reason, so they put the slimmest line just on the end of the tail whenever it wears a bit, which keeps their boards going for a long, long time.
The other one, which was way more fun to me, was when someone was done with the board, usually the tail worn down and nose still fairly fresh looking, was turn it around and cut it down, even just a tiny bit to make a shaped cruiser or "fun board" which lots of the kids we skate with had almost more fun on than their normal board. Given the kids didn't mind what the concave was like, they could easily skate the noses of the boards without it feeling funny, so we would often just cut the worn tail just a little or do something to make it look more like a stubby nose, maybe re grip if needed then set them up or even pass them on to the kids to ride as their normal board, in some cases.
Some of those boards lasted so much longer for those kids than for the guy who skated them first, so it was good to do something a little creative, as well as supply kids with fun boards, which helped everyone. Most of the kids were more beginners / transition based so they loved them, but even some of the better kids said they liked the "fun boards" better than a normal board anyway.
Spot selection can have a huge impact on how long a board will last too. If it is crusty concrete, you could go through a layer every session, which means a board will last about a week at most before needing to change it out, as per some places and people I know.
Not sure how or when it started, but having your board pop off the nose for pop shovits as the first trick in the line seemed to come about around the same time as lines were being filmed (definitely mid 90s for us growing up), so I got so used to doing that it almost feels funny doing them off the tail nowdays, but that alone should help the board last a little longer too.