Well, we start looking for rhymes, I think. Rhyme and rhythm is what makes a song - it does not have to rhyme, of course, especially not if the rhytm is good! But it does help, particularly if you want it to be catchy!

So, I was thining, maybe somthing to begin with like...

I knew a girl, a clever girl,
From a town of cold and rain
Oh she smiled at me, and she laughed at me,
But our hearts they were the same.

Her eyes were bright, her tongue was sharp
Her mind of quicksilver made
Oh she smiled at me, and she argued with me
And we love the same video games