Getting away from static mockups. Challenging myself to go from prototypes (Axure) to creating beautiful UI elements (Fireworks) with a service like typecast for finalizing details. This allows content to dictate more of the layout in a real time environment which is the live scenario. Ideally, once this mockup is tested and approved, it's ready to launch as-is.
I will be the first to say that although I've been using Axure and rapid prototyping for early web project phases, I have still be in the habit of designing the visual detailed layout in fireworks for approval. While this may work for me to continue doing to get my thoughts and ideas into visual elements quickly as a whole picture, I'm going to put an effort forward to pull those UI elements into the same prototype that was designed with dimensions and markup already in tact (where applicable). This may mean cleaning up generated HTML, but I honestly haven't looked at the code that Axure outputs in detail yet. Ideally at this point my mockup can continue to live and breath while using less and less imagery (files) combined with CSS visual styles. Then I'm looking to bring in tools like typecast on projects where I'm able to open up to web font options*. In fact, that tool can still be super useful for designing on the fly even using traditional web fonts to get the details just right in the layout.
This idea also supports somewhat responsive design in that content is built-in. The only issue I can see with this besides new adoption is the lack of content. Unfortunately there are still so many situations where designers are designing with placeholder content, which is just awful. Content first (awareness and understanding from teams working with web professionals) is another issue which I'd love to tackle another day for a solution to support understanding among collaboration teams.
* I say this for branding reasons. I work on many projects where the company has officially chosen a traditionally supported basic web font for all web properties and until that is revisited web fonts aren't an option for design. In addition, many brands that have other typefaces for their brand offline but are not created as web fonts yet.
Love hearing what others are doing!