^^ My livery for the Airbus A320. Note that this is my first time liverying, but I think I did a half-decent job on it. The base model was purchased, everything else on it was done by me. Credit to the group who created it, Dantech.
Possibly you could try adding more colors, as you’re using just grey and blue it seems like. Change the little trees, they look too blocky. Maybe add a little bit of carpet around the seating areas, for example, a piece of carpet around each seating area. There’s all that open space on the right. On the right, you could add TVs connected to the wall, and maybe an aquarium. Or, you could move the seats against the wall and add some stuff in the middle like aquariums, a little version of the plane in a glass box similar to the aquarium, and information about it. A lot more could be added, this is just all I could think of. Have a nice day!