Tricks for Writing Humor? Anyone?

I have always wanted to write a humorous book. When I do find the time to watch television I mostly watch cartoons and humorous late night shows. I'm great when it comes to having funny conversations with people. I can say something witty rather quickly and I can write some very hilarious radio commercials. However, when I try to sit down and think of something funny to write about for a novel, nothing flows out. Even when I think of funny situations that have happened to me, I can't think of a way to alter it into an interesting plot. Any tips?

Make a humorous situation but don't play it up as humorous.

Like let's say a giant bust of Ben Stiller from Zoolander must be thrown into a wood-chipper in order to obtain some MacGuffin for your story. That's kinda funny on its own but it's better if you make the entire affair this huge tearful goodbye, ending with a selfless heroic sacrifice, and then later hold a solemn funeral. Play it straight.

Don't look for a humorous plot.
Be aware of the difference between 'humour' and 'wit' - the latter can be caustic and unpleasant.
And, (quoting the character of chief comedian at the BBC parody show "Hi-de-Hi!" based on Butlions holiday camp - "Spike, if you're going to be funny - keep the reality in it. It's not funny of there's no reality!" (Spike being the camp's junior comedian.

I like breaking the 4th wall in my humourous books on occasion. Mostly characters don't know they're in books, after all.

Be absurd. Why not go for the gusto with some poor rhyming butt bros?

Come up with a plot that's not funny and is just a plot, then you can add all the humour in with the characters and the crazy situations they find themselves in. Write a list of the funny things you've said in conversations and try to fit them into the story somehow. the more random the better. Hope that helps

I often mix Breaking the Fourth Wall and Genre Savvy in my stories:My characters encounter cliches named after TV Tropes articles.

[Inspired by the dare to have a gun belonging to someone called Chekov.]

For example, someone called MacGuffin injects basilisk poison into a dragon's tooth to create a twisted bone shard that will turn anything it touches to dust, except ice. The protagonist and antagonist treat MacGuffin's creation as a MacGuffin, racing to reach the chest made of ice its held in.

During the course of the book, a tyrant overlord mentions that he found a battered copy of the Evil Overlord List in another dimension.

Someone gains a new superpower just as the clock strikes eleven(my personal favorite because it's subtle).