I believe that if you think an idea is funny, but it's not getting laughs, then most likely it's funny, but it's just missing an element that is needed to trigger the laugh.
In my classes, part of what we study is WHY people laugh. What triggers that?
When you understand that at its most intrinsic level you can begin to make changes to a joke to take it from a semi-chuckle (because it's a funny idea) to a triggered laugh because it a funny joke.
Here's an example:
There are a ton of ways an emcee can ruin the introduction for a comedian. They can bomb a joke then immediately bring you up. They can create an incident with someone in the audience and bring you up on a sour note. They can screw up your name or screw up your intro.
They can do a backwards intro. A backwards intro is where they mention your name first and the audience doesn't feel the impulse to applaud...
It's amazing to watch someone who's developing their skill at writing. They could crack a great joke right in front of you. And the moment you ask them to write it down, they fall back on their learning of writing in school, trying to use correct punctuation, grammar, etc., and they over write the joke.
That can kill the joke.
This is what you can do to fix it...
A writer interested in writing for Late Night TV, should be paying close attention to the movements that happen behind the scenes just like a market investor eyes the NYSE or the NASDAQ.
Because turning $11k into $200k over a period of 11 years is a sweet investment, but a job writing in Late Night TV can turn $0 into $200k in a year, because that's the minimum salary for a staff writer working in Late Night.
So a writer should be paying close attention to the Late Night TV market, because drama is happening big time over at CBS.