What's the Best Way to Cover Up Spider Veins?

We recommend treatments of sclerotherapy and/or laser for spider veins, followed by about a weeks worth of wearing compression stocking.
If you just wanted to "cover up" the spider veins, consider wearing compression stockings which are thick enough to "cover" them up.
I don't recommend the common practice of tanning to help hide spider veins. Tanning in itself has some risks, and tanning then would get in the way of laser treatments. Perhaps for "cover up" you could try "fake tan" or tinted sun block!

Get them treated with sclerotherapy or laser vein therapy. It is better not to mask them because as time goes on, they can get matted and as they break down, blood will extravasate and the hemosiderin deposition can cause brown dicoloration of the skin which may not be treatable.

Masking them is like putting your head in the sand like an ostrich and ignoring the problem.