Thanks to my pal @kenkenbeauty on Instagram for the following tips!
Starting today, receive 30% off sitewide at Sigma HERE with code SAVE30 (according to my archives, the last time Sigma had a 30% off sale was December 7, 2015, and it was only for select items). Free shipping on orders $50+. This code also applies to items on the sale page HERE. There are also various freebies HERE that you will have the choice to select depending on how much you spend ($30, $50, $100, and $150). I believe this sale is valid through July 4th.
Thanks to reader @makeupbysadieg on Instagram for the tip that all of the Sigma products on the Dermstore site HERE are now 30% off (no code required, nor can you use a code for an additional percentage off). Free shipping on all orders at Dermstore (owned by Target), no minimum required. Also, if you spend $50+ on Sigma, you will receive a FREE Mini Glove ($5 value), which will be automatically added to your cart.
Thanks again, @kenkenbeauty and @makeupbysadieg, for the hot tips!