I'm in 5th, but my kids couldn't even handle the "5 senses chart." I've had to go back to VERY basic basics. So, just in case that's your situation, here's what I did.
I started with vivid verbs
and put words like "went" "said" or "got" on the board, and I had them brainstorm more descriptive ways to say those ("raced" "stammered" or "received"). I let them act out the words. I would give a "boring verb" and tell a student to act it out. Then I'd tell them they were doing it wrong! (I'd tell them to walk, for example.) Did that a couple times. They'd get confused, and then I'd tell them the vivid verb ("shuffle" or "limp" or whatever). That demonstrated how important it was to be vivid/exact! We want our reader to know exactly what we mean when we write.
We did tons of practice with that. Then I had them choose 4 vivid verbs and find a picture in a magazine or newspaper that illustrated that vivid verb and explain why. (For example, some of my students picked a picture of two players in a football game for "battle." They explained that the football game was like a war for rival teams.
Did the same thing with exciting adjectives/adverbs
("fire-engine red" instead of "very red" or "bulbous" instead of "round"). I had them draw what I told them with the "boring" words (round plate) and then tell them it was wrong again.
Then on to exact nouns
... "firefighter" instead of "man" or "pediatrician" instead of "doctor." More drawing, too.
Then we started creating sentences using the VV, EA, and EN words. Four weeks later
(1 hr a day/ 2x a week), we are working on descriptive paragraphs. But their writing is exponentially better.