I just was on a flight with my kids and didn't see anyone with a mask...
What I did was before I let my kids sit down, I pulled out my lysol wipes and wiped everything down...the tray table, the arm rests, the seat belts, the seat, the window and ledge and all the knobs/buttons for lights and fan. Then, I hand sanitized my kids and were set. People snickered when then saw me frantically wiping everything down and you could really smell the lysol...but I have kids that get sick easily and wanted to do what I could to try and prevent them getting sick...even if it seems silly.
Everyone is saying that handwashing is key...so keep those hands clean and out of your eyes, nose and mouth and that should help a great deal.