I've come up with a commonsensical procedure for manufacturing observational humor. In fact, it's so commonsensical that I refuse to believe I'm the first to invent it. It won't catapult you to the standup A-list, but as long as you are not an introvert and you have a sense of humor, you can string jokes together into bits and bits together into sets and do a fair job at some open mic.

Think of something you are cranky about, or one of those anecdotes you always pull out at parties. Look at its causes or predict likely outcomes of this incongruity. Extrapolate into absurdity, preferably retaining a kernel of the original truth-in-paradox. Make multiple jokes about each premise for a cascade of punchlines at the climax of each bit. Repeat for each topic.

Construct shortest-path segues, turning your group of unrelated bits into a set. Practice saying your set in a little speech to yourself or to friends who have a sense of humor, testing rhythm and diction, iterating through better and better versions of the set. Preferably you'll have at least three punchlines per minute. Once it reliably makes people laugh, it might not make you laugh anymore, but it's ready for the stage.