Korra's never been the type to wear makeup by choice. And while she has a hard time understanding the need for it, there's nothing that she loves more than watching a certain someone bend towards a mirror, a fine sort of concentration laid out on the features of her face.
Her hair is usually tied up, for convenience. Most likely to keep the hair from getting eyeshadow or lipstick in it but to Korra, it just makes it easier for her to stare at Asami's slender neck. Most of the time, she is fully dressed and carefully selecting colors to match her outfit. Light brushes on the cheeks to start, focused application for the eyes, and flirtation with the lipstick. The Avatar knows this process pretty well for someone who never uses the product.
Other times Asami will put on makeup fresh out of the shower, her hair damp and a silky red bathrobe covering her body. This often happens when Asami has just bought a new color of eyeshadow or lipstick, and she wants to color co-ordinate her clothes to the makeup. The heiress thinks that the Avatar does not notice, but Korra pays attention to every detail when it comes to Asami because there is just so much to take in. She wonders if a lifetime will be long enough for all there is to discover.
Special occasions are Korra's favorite, because that means that Asami will set aside a good length of time to get ready. At first, Korra found it unnecessary to take so long but then she walked into the bedroom where Asami was standing in the closet quietly singing to herself as she carefully picked out a gown. Korra decided then and there to never complain about it again and began to set aside large amounts of time to get ready too, but for an entirely different reason. One involving the way that Asami's voice made her feel like everything was beautiful in the world.
On the flip side, Asami likes to watch Korra too. Her observations lie in occasional glances and calculated stares when the other is locked into her own world. Korra diligently makes sure her garments have no holes, and that the beads are not out of place. No makeup and little jewelry, mostly just herself. Asami marvels at how Korra can be so tough and equally feminine simultaneously. It was something that as a child, she was told was not possible. She wonders if only the Avatar can manage such excellence, or if it's just Korra. She thinks of the time that her love lost three fourths of her bending abilities, and remembers that without that powerful substance of change that was fire, earth and water bending, Korra was still magnificent.
As she remembers that sad moment, she looks over at the Avatar, who is leaning up against a doorframe, ready for the occasion, and entirely patient as was evident by the contentment across her lovely face. She sees Asami's hesitant look and asks worriedly, "What's the matter?"
Asami smiles coyly and adds the finishing touches to her outfit, a dark dress with an open back. "Oh, you know. You're just standing there like the most beautiful person in the world is all."
Korra chuckles and walks over to her date. She gently places a hand on Asami's back and stands on her toes to plant a kiss on her cheek. Asami closes her eyes at the gentleness of the hand and the lips on her skin as Korra moves from her cheek to her shoulders and finally brushes her hair aside to rest on the back of her neck. Asami breathes as they stand there, close to each other, Korra's arms around Asami, resting her head on the back of her shoulders. After a sound moment, Asami releases herself from Korra's hold and turns around. From here, she gently tilts Korra's face up with a finger under her chin and kisses her.
This was the only method of makeup application that Korra felt happy to oblige