Plan your budget accordingly so that you don't get your hopes too high or settle for less than you deserve. That is, plan your budget based on what you can afford. If a half-million dollar home is in your dreams, make sure you can finance it - visit your accountant and bank manager beforehand so you know what budget you can realistically work with.
When you are searching for a designer, search for one that is local to the area where you want your home built. Typically, local designers will have a better knowledge of the region, the laws, and the other issues surrounding your new house building project.
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.
Nowadays architectural soundness has acquired a new meaning, with the advent of sustainable designing. A dwelling sheathed in solar panels has a very different aesthetic than the usual suburban house. Multi-unit housing which eliminates the thermal bridges created by extensive glazing and concrete decks do not share the aesthetic of glass paneled high rise towers. Passive solar designs often borrow elements from local architectural styles to address local climactic conditions.