Lip service Lesson #1: Don't string all your pearls on one necklace (translation: Don't put all your eggs in one basket!) proverbial I know, I never understood why my father was always so adamant about it, until now. Whether it's your professional or private life, don't ever not have a fall back plan, variety is after all the spice of life.
Fashion: try new things, don't get caught up in the same boring routine, check out new stores, and new styles, who knows you might find something you really love.
Love: one guy isn't a good enough prospect, don't count on him to be your prince charming, because well fairy tales don't really exist, sorry. For all intensive purposes I believe in monogamy (as an end result), but what I don't believe in is only dating exclusively, and filling your mind with the thoughts of only one person when you've got your whole life ahead of you.
Career Planning: it's all good and well to have career plans, because Ambition is a wonderful thing, but there's no excuse not to have a plan B, sometimes they'll save your life.
Whatever the case may be, don't lock yourself up into an all or nothing situation, you set yourself up for disappointment 99.9% of the time.