Simplest ways to reduce appearance of spider veins?

Sclerotherapy/laser: The best two modalities are injection with a sclerotherapeutic agent like hypertonic saline, or targeted laser treatment.

A number of things: Although several things have been mentioned in other answers, the simplest way to reduce the appearance of spider veins would be to use make-up. If you want to do something that is more long lasting, i would recommend sclerotherapy.

Dr Wright agreed

Reduction of spiders: Spider veins are a very common problem and there are many causes including hereditary, aging, pregnancies and even sun exposure. Treatment may include compression stockings but this is a temporizing measures. For more definitive treatment, sclerotherapy o topical laser or micro needle rf would be a better choice. However, this is a process and may require multiple sessions.

Sclero: Sclerotherapy (injection of a medicine in the vein) is your best option. It works pretty well. Laser is good also. Treatments are simple and although it takes awhile to heal, the results are pretty good.