All you have to do is, well, choose your preferred Galaxy S10e, S10, or S10+ configuration and order it on Amazon right now. Only select color options are currently on sale depending on which of the three you expect to fit your needs best and how much storage space you want. The 5.8-inch S10e, for instance, can be purchased for 100 bucks less than usual with 128 gigs of digital hoarding room in a Prism White paint job only, while the same markdown applies to the 256GB config in white, blue, and black hues.
The 6.1-inch Galaxy S10 is available at $100 off in black, blue, and white as far as both 128 and 512GB versions are concerned, with the Prism Blue 6.4-inch Galaxy S10+ marked down by the same amount in an entry-level 128 gig SKU. If you'd rather get a Prism Black S10+ capable of accommodating 128GB of data internally, you'll need to settle for a more modest $50 discount. As for 512GB and 1TB variants of this blazing fast big guy, you can get either of them for $100 less than usual with swanky Ceramic White or Ceramic Black exteriors.
It goes without saying these are far from the best deals out there strictly talking about how much money you stand to save, but they're also arguably the most straightforward discounts available today. Sometimes, that's far more important than being able to save an extra 100 or 200 bucks by accepting a bunch of compromises and cutting various corners.