If you find yourself running out of steam with the first four words you pick, feel free to pick some more out. You could even pick out 4 words per stanza. Remember, stanza originally meant “room” in Italian. Each stanza is a distinct room that your reader can enter and experience, so picking out different words is a legitimate way to make each stanza unique. However, make sure you have an overarching theme that unites the poem as a whole.