This style of architecture became quite popular in the United States between the 1890's and 1940's. Interiors, because they are small, can give a cluttered but utterly functional appearance, with artistic niches and nooks, and knick-knick decor. Cottages are designed for a relaxed, simple lifestyle - places to come home to, kick off your shoes, and flop on the furniture. They are not designed to impress other people, but to make their owners feel good. Cottage living often involves gardening, and most cottage owners spend their weekends and vacations outside in their backyards, digging in the dirt and growing flowers and vegetables.
Ranch style architecture originated in the United States in the 1920's, and it became very popular after World War II as cities expanded into suburbs and inexpensive tract homes were needed by a growing populace. Ranch style houses are most popular where land is inexpensive and the weather is mild, since these homes particularly lend themselves to outdoor living. The low, earth hugging look with clean, modern lines of the ranch style is derived from Frank Lloyd Wright's prairie style architecture.
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.