Shopify Pipeline theme developer GroupThought has a useful modification to a tutorial on Shopify detailing how to change the product form variant selector when clicking product thumbnails.
It's surprisingly easy to set up this effective user experience. If you're looking to go a step further and educate yourself, the GroupThought article, geared towards the popular Pipeline theme in particular is a great place to learn how to wrangle Liquid's product and variants objects by way of JavaScript.
