The major lesson will be to ask for the sale. And work that into the conversation, so less "that'll be $99", but more like "So, would you like the blue or pink one?" If you don't ask for the sale, you won't get it. If you're solving a problem, making the sale is helping people. They came to you for help for a reason, so treat them well.
Yes, you should ask for the sale. But "So, would you like the blue or pink one?" might come across as a bit pushy. "would you like to discuss pricing?" is more of a soft close.
Car sales is another obvious example. They don't talk price until you're committed (at least in principal) to purchasing the car.