Look for reputable designers. There are hundreds of different builders out there and every single one has a different history and reputation within the community. If you take the time to check out all of the available designers, you should have no trouble finding the best in the industry.
Exposed wooden or steel beams, flat roofs with large overhangs, and split levels to take advantage of the terrain, are also common accents associated with the contemporary style.
Given their professional experience in house designing, it can be helpful to hear why certain elements will and will not work as you may envision. Your architect will be able to show you 3D walk through plans too. This can be useful exercise to examine sun patterns at different times of day and get a feel for the scale of your future modern home.
Plan ahead and know what you want. If you take the time to look at different modern home plans, you will have a much better idea of what you can expect from your designer. Once you know what you want, you can find a professional that fits your style and demands.