Poetry / Thesis ideas for Comparing and Contrasting two poems [14]

Help in compare and contrast poem essays.

Hello, please I need help on how to write compare and contrast essays between two poems. The poems I have are; Fifteen by William Stafford and The Seven Ages of Man by William Shakespeare. I already have my rough draft, but I don't know how to expand on it. Do I just need to explain the meaning of literary devices? Please, I need your help.

Thanks.