Onew: he would try to bake a cake, but fail miserably. He would scream around the kitchen, trying to get the smoke to clear out. this is your cue to walk in, and wide eyed ask what exactly is going on. "Ah.. Nothing jagi! Just.. Ah.. Trying a science experiment?" You would scold him for not being careful, and then scold him for lying to you cause that obviously was a lame ass excuse. He would pout, and later go to the grocery store to buy you a double decker cake in your favorite flavor, settling for decorating it. (Aka writing your name badly in colored icing and placing candles everywhere.)
Jonghyun: his first though is to give you his body for a present, but he knows how badly that went last year and he doesn't want to look "selfish" again. He still doesn't get it, but goes shopping at a jewelry store, looking at rings. he wanted a simple promise ring, but not exactly knowing what a promise ring was, came home with a wedding ring. You were in for a surprise, and so was he. "Aish so expensive for a simple couples ring? I hope _____ likes it."
Key: being the fashionista he is, he went to the mall for a shopping spree. he had seen your wardrobe, and guuurl it was time for a change. So last season. He would go to his favorite stpres, stocking up on the latest fashions, before finally going to his personal tailor (having secretly took your measurements in your sleep. Not creepy if he loves you right?) to make you a custom outfit that would wow the press the next time he took you to a show or event. It's a present for him and you, while not looking as selfish as jonghyuns "gift" to his jagi that one year. Secretly selfish is keys specialty.
Minho: he would be looking for puppies for you two, after months of talking about it. He figured out your favorite puppy, and had located a breeder near him. The breeder would start with a "you know, plenty of people are lined up for this puppy, but you're minho of shinee! How could I say no?" Minhos conscious would be nagging about how all the other people probably would be dissapointed. "it's for jagi. ____ deserves it." He would repeat in his head, but finally decide that maybe you would settle for a rescue. He had always wanted one, and even though you had a favorite breed of puppy, you had never expressed dislike for rescues. He left for the shelter and picked out a nice healty puppy, then brought them home to surprise you.
Taemin: the little baby he is would be so confused wondering what to get you. "Aish.. What does ___ like? Maybe I should just get a bunch of banana milk we could share." (Yes selfish again.) he would wait until the last minute, before finally getting something random from the store. It's the thought that counts, right? He would also probably throw in a handmade gift from him to you. "Ah, thank you for the.. Juicer?" "There's something else too." You would blush. "Oh.. The ball of painted paper isn't.. Oh. I see. Yea, thank you Taemin. Very sweet of you."