If you’re not used to it, speaking with clarity is like speaking in a foreign language that you’ve recently started to learn. It’s hard to find the right words and you need to slow down significantly.
But, of course, just like other languages you can learn it.
It requires
i. learning the vocabulary so that you know how to replace complex words with simple ones and
ii. actively using them.
In other words: just like with any other new language you learn, you need to practice speaking it.
The difference to other foreign languages, of course, is that reading something that’s clear is not at all difficult. Unlike other foreign languages, you immediately understand something that’s written in Clarity.