I usually encourage my students to pick two or three closely-related poetic elements on which to focus in a thesis, like:
- Speaker, Audience, Tone
- Metaphor, Imagery, and Theme
- Prosody: Meter and Sound Effects
"My Papa's Waltz" presents a quandary among readers: younger readers fear the father, while older readers see him as relatively harmless. Do you see him as an alcoholic child-abuser or a fun-loving, though rowdy, father? So, take a position and, using approach #1 or #2 above, support it with textual support.
I find the poem interesting from a structural level: the first two lines of each stanza seem to be carefree, but the last two lines have slight turns to a darker side. Why does Roethke do this? Is there a musical or metrical connection to this approach?
Also, look what other editors have said about how to analyze the poem. The TPCSTT method always leads to a good thesis as well. Again, only focus on two or three of these:
Title: Ponder the title before reading the poem
Paraphrase: Translate the poem into your own words
Connotation: Contemplate the poem for meaning beyond the literal level
Attitude: Observe both the speaker’s and the poet’s attitude (tone).
Shifts: Note shifts in speakers and attitudes or form
Title: Examine the title again, this time on an interpretive level
Theme: Determine what the poet is saying