For me at this point I do all the jokes for me, not in a self-indulgent way, but there's nothing I say just to get a laugh. I do a joke because it's funny or clever or meaningful to me.
That hasn't always been the case. For years it was a mixed bag. I did some jokes just because they worked and gave me that oxygen we need. I was looking to get hired, which is a terrible motivator for an artist, but I've evolved, hopefully.
The greatest thing I ever heard related to this was in the Curb Your Enthusiasm pilot. Someone, it may have been Jerry Seinfeld, said that Larry had unwavering convictions as to what he thought was funny. That's essential to becoming unique/original and it's hard to stay true to in an environment where the audience's laughter is (wrongly I feel) considered so important in measuring a performer's talents.
Part of the series Comedy Writing by Mike Bent which looks pretty decent. Below, an excerpt from Everything You Know is Wrong by Bent.
The members of Firesign Theater said it all when they named their 1974 album “Everything You Know is Wrong.” That's the attitude you have to take. You need to question everything around you. You can't just accept things as they are; you need to consistently challenge the status quo. That doesn't mean you have to be an outcast from society; it just means you need to look at things differently.
The full "Comedy Writing" series.