The veins in my hands are getting more prominent as I age, both bluer and puffier. I remember years ago, my grandmother telling me she would raise her arms straight up and let all of the blood drain out of the veins in the hands if she was having any picture with her hands showing, or if she was sitting at a table, she would make sure to put her elbows on the table and keep her hands raised so that the blood rushes down. That definitely makes a huge improvement in the look, but is not practical in most situations!