I think Polish girls like good decent boys first of all
So, the boys should be: mature, responsible, caring. Also, non-drinkers. Cleanliness is a must. And loyalty is very important too. They should have a sense of humour. If they possess the before mentioned qualities, they can smoke or swear, though. Don`t need to be very handsome.
These are preferred personality traits for prospective husbands from my female students during class tutor lessons. Hardly any girls mentioned kids etc - they don`t think about it yet.