Developing in DirectX 12 compared to DirectX 11 is certainly a different animal completely, And Vulkan isn't actually officially out quite yet, but AMD is going to help out those budding developers make that transition by giving a talk at GDC about the lessons they learned internally.
Matthaeus Chajdas, who is very well informed on the topic of these new API's, and has had a hand in creating Mantle, will be giving the talk. According to the GDC schedule, the lecture he'll give will go over a lot of the low-level ideas that can make DX12 and Vulkan much better and much more efficient.
Matthaeus will go over the first round of games that're in development and talk about what works and what doesn't work so well. He's got a lot of knowledge on the subject, and if you're a developer of any kind looking to better your understanding of the two new low-level API's, then this is the lecture to attend. Having had the chance to chat with him about even simple concepts was fascinating. Just remember that these lectures are designed for those with development experience.