I started doing this at university.
I had a teacher who disliked me and gave me bad grades and I could not understand why. Eventually I realized that he hated the way I verbalized my thoughts. My sentences were too precise, too long and employed too exact a vocabulary. So I changed the way I wrote and talked.
In writing, I broke up complex ideas into short fragments and expressed these in short sentences. What had once been a slightly baroque sentence would now be a five sentence paragraph.
In speech, I imitated my peers and introduced "um," "uh," "like" and "you know" into my language.
Whereas I had once, perhaps pedantically, composed large and complex sentences that carried the burden of my thinking from my mouth and hurled it into the interpersonal void like great birds with steadily beating wings of thesis and antithesis who navigate the long migratory routes across the trackless depths of the ocean until at last they descend on a distant shore and birth synthesis and understanding in the minds of my fellows, I would now toss out short and pithy utterances and lob them softly at my audience, leavening them with a steady stream of um, like, and you know to soften their impact still further.
Now, I like, kind of say a little thing, you know? And, um, like let the, uh, guy I'm like, talking to, you know, figure it out.
People like me more this way. And brevity is the soul of wit.
Short sentences really are better, though there may be some ideal middle ground.
The peragraph length example above is a bit purple, and I probably never really went quite that far, but for length and complexity, it's about right