Start with familiar person, place, or thing.
A young woman came into the bookstore where I work looking for some sort of guided workbook that show her different poetic forms and give her room to try them out, see what fit. Not idea prompts. Form prompts.
Be still, my heart.
There are lots of guided journals out there, some that even focus on poetry writing. But their focus is the idea or motivation behind the writing, not the craft of writing. Until such a craft-focused guided journal exists, here are three places you can look for poetic forms to master.
Persons of Interest
What poets do you admire? What poetic forms do they use? What poets do they read and what forms do those poets use?
Shakespeare worked in blank verse and came up with with his own rhyme scheme for composing sonnets. Samantha Holmes writes poems that are short-and-sweet and IG-worthy.
Pick someone to be your teacher, and let what they did be your guide.
A Place in the Sun
Where are you from? Where are your forebears from? Where have you always wanted to go?
Italy invented the sonnet and the English came up with several variations, Russia’s got a sonnet form as well. The Japanese have their famous haiku and English-speaking poets (Americans in particular) created a variation using 15 syllables instead of 15 ons (because they are in fact two different linguistic units).
You could throw a dart at an atlas and then google what poetic forms originated there or were further developed there, and then you just plug away at it til you feel like comfortable in your new literary landscape.
Any Old Thing
What poetic forms can you name off the top of your head? What objects in your home get you tapping your toes? Ever dork out over the prevalence of the Golden Ratio in nature?
You can work your way through a book of nursery rhymes and rewrite them to be complete nonsense. You can write a line of verse for every second in a twelve-hour period and call it an epic. (I’ve literally done both of these, guess which one’s still in progress.)
If you can think it, count it, turn it inside out, it’s a poetic form and you can play with it all the livelong day.