Acrostics are perverse. Your choice of keywords is limited by the first letter of each line. When you start to write, you can pretty much guarantee that none of the keywords you want to use will start with the available letters. This is a real problem, but also a spur to creativity. Re-think the theme from a different angle. Look for an original insight, a new way in. Eventually, after several failed attempts, there will be a spark. A new and thought-provoking set of keywords will start to emerge which makes the writer and reader look at the theme from a non-obvious angle.
Then there is the question of whether the acrostic should rhyme. It doesn’t have to; sometimes an acrostic is better for not rhyming, provided it has some sort of rhythm and flow. However, I now prefer to make the lines rhyme – much more difficult but, again, it forces invention, creativity and seeing familiar themes from unexpected angles. And don’t be afraid to use aids. I often resort to https://www.rhymezone.com/ which not only suggests rhyming words, but also antonyms and synonyms.