There are many many different poetic forms, some are long and some are short with more rhyme and rhythm schemes than you can shake a stick at! An interesting exercise is to find a form you have never written before and exploring it. Read examples and the tech breakdowns of how it works. Wikipedia can be a good starting point and don’t forget that your native tongue and time are not the only languages and time periods to give birth to poetry – ancient forms and different cultures offer a whole new variety of poetry to enjoy and try.