Actions always speak louder than words. Your undivided attention tells a man how much he is important to you for example if you are checking your phone or texting while talking to him he’ll definitely think that his saying is no more important than your texting. If you put your phone on side table make eye contact and listen everything he said very carefully that’ll make him more than happy.
Taking care of his favorite meal, movies, TV shows and everything he likes will tell him that you are taking care of him. And there are many other things you can do such as wearing that dress he loves you in, taking care of yourself, complimenting him, encouraging him to take time for himself, asking his advice, thanking him for the little things, as sharyn's slant mention this is an open ended question :)