When dating someone new, the little things pave the way for the relationship. Does he bring you flowers once in a while? Post photos of the two of you to social media for his friends to see? Tell you you're special? Wear a certain cologne because he knows you like it? Surprise you with your favorite treat when you're feeling down? I hope the answer is yes. That doesn't mean to say they have to be kept up in the relationship because as the dating progresses, you get a sense of how you feel about each other without those tokens of affection.
But the little things shouldn't go away completely. Any relationship needs effort and even though you might not need to constantly reaffirmation that you like/love each other, sometimes it's nice to have it. They invoke the honeymoon feeling you had during the first few weeks or months of the dating process. It's nice to know someone cares about your feelings and is willing to surprise you with small gestures. Changing a profile picture to the two of you? It doesn't seem like much, but it means that you want to show off that you are with each other and that you're proud to be together. A random kiss on the forehead, it could mean the world to someone. That doesn't mean you have to go all Heath Ledger in 10 Things I Hate About You and perform a song to win someone over, but don't forget to acknowledge you still like each other ever so often.
The little things go both ways. He can't just keep bringing you flowers if you never do anything in return like send him cute texts during the day to let him know you're thinking about him. No matter how long a relationship lasts, the little things are needed. They say to your significant other: "Hey! I'm thinking about you because you're a special person and I'm glad you're in my life."
The little things (a sweet text, a romantic gesture, spending the weekend doing what he/she wants etc.) are important. Even if you feel like you're secure in your relationship and don't think you need to do them anymore, you do. They make every relationship just that more exciting and if you like/love someone, don't you want to do anything to see them smile?
Don't be afraid to show your person that you care, in any way you want. It's never too late for the small things.