Here's a little trick that I use to help me remember birthdays and gift ideas.
I create a yearly repeating task for each person in my life. This is pretty normal, but what I also do is use the notes field for each person's task to keep track of gift ideas. Whenever I think of something that this person may like, I add it to the note. That way, whenever I need a gift I can quickly reference the note and pick something out. I also have a folder called "Birthdays & Anniversaries" that I use to organize all these types of tasks so that I can quickly find them when the time is right.