It took me a long time to learn these things, and I think it might help your boyfriend to know them, too:
1) Women typically value several small deeds over one large one. A small note, a thoughtful text, take the garbage out, pick up around the house, ask how your day was - these things will go a lot further than one large thing that you think is more impressive.
2) Women often want to talk just to talk. You don’t have to solve anything. You just have to listen and try to show that you understand how she feels. You can mention a time when you felt the same way, but keep it brief and let her talk.
3) Make sure the last thing you say to her is always how you feel about her. Do this when you leave in the morning, when you go to bed at night, when you go out on a walk, etc.
4) It doesn’t matter if you just met, have been together a while, or have been married for decades, you always need to continue to court her. Always treat her like you’re trying to get her to marry you.