So that you know what needs to be addressed in regards to the poetic devices, defining the poetic devices in question is important.
A simile is the comparison between two things using the words "like" or "as" in the comparison. A metaphor is similar, but the comparison does not require the words "like" or "as." Alliteration is the repetition of a consonant sound within a line of poetry.
Based upon these definitions, one can begin to construct a poem where one is an inanimate object.
First, choose an object which you like. It will be much easier to realte to the poem and the object. Next, think about the qualities of the object which mirror your own qualities. Lastly, make a list of descriptors which you can use to describe both yourself and the object.
Here is an example:
Tick-tock time ticks (alliteration)
I cannot stop my face from showing
How time flies.
My hands spin like a compass (simile)
Unable to make a second last any longer than it should
I am Father Time. (metaphor)