Blues poems are different from the norm and are about pain and suffering. You must be inspired by an event in life, be it of any kind that has left an effect in some way on your life. Inspiration is an important part of poetry and helps you bring out your sensitive side which is very important for any poet.
Understand the Genre
Understand the blues poems and see the structure in which they are written. Also, understand what has inspired this kind of poetry to understand the spirit of the genre. Traditionally the blues poems highlighted the plights faced by the African-Americans but now the genre is used for a tragic event of any nature and is not restricted in any manner.
Once you are familiar with the format of the blues poem, you need to pick a subject on which to write. If you have gone through a traumatic experience in life, you can share it through the words in the form of a poem that you will be writing.
If an event that is completely or somewhat unrelated to you has made a difference or makes you heart move when you hear about it or think about it, you can also write your poem about that.
Focus on the given point is an important part of the blues poem. You may write the same line twice before delivering the idea in the third to create an effect and to stress upon the original idea. This will get the poem into a nice flow. Continue with this flow throughout the poem to get the message across. This method is highly effective and is well appreciated.