You have to write well because writing is essentially crystalized thought. Whatever beautiful ideas exist in your head are only known by the words you write.
You should tell a story. It should include where you've been, who you are, and where you're going. It's helpful to think about the essay as an argument. You have a thesis to prove: that you know what you're getting yourself into and that you're capable of succeeding. Each past activity you mention is really evidence of your argument that you know what you're doing. Each story should support and build on the central thesis. Rather than tell what you did, rather than show what you did, just make it clear how the story supports your intent.
The problem with a lot of personal statements is they just repeat information already in their activity list. You don't have to be overly creative with your story, but the personal statement gives an opportunity to explain how you got started and what led you to engage with each experience and how each experience developed you.
One way to add artistic sophistication to your essay without distracting from the content is to have an extended metaphor. The extended metaphor basically means you open your essay with a metaphor and close it by referencing the same metaphor. I picked up on this pattern after reading a couple long form journalism articles from the Atlantic or something and realized they often do this. When they make a small reference to the opening story, it feels all warm and cozy.