Love Is a Verb
There's not a person on the planet that doesn't want to feel important and special. That includes the people you live with.
Let them know.
Write a simple note telling your child how much you love him. Include something unique about him that you appreciate. Leave it on his bed so he'll find it at bedtime.
Tell your daughter that you'll spend 30 minutes playing anything she wants to play, and she gets to call the shots. Her game. Her rules. And then spend 30 minutes following her lead with no complaints, no redirects, no change of plans.
Ask your significant other out on a date, and let her/him choose a favorite event or activity. Give them two to three hours of your time, your attention, and your willingness to enjoy being together.
These gifts are inexpensive and often overlooked, but they feel amazing to receive. And your loved one will feel important to you. Special. And so very loved.