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.
If you are looking at building a family home for example, then storage space for recreational gear such as bikes, boats and tents should be considered, as should backyard space for outdoor activities.
Modern home plans are created en masse to suit the needs of people who don't want to customise the design of their new home. However, if you have chosen to customise and personalise your floor plan, you can do that too as long as you are prepared to tell the architect what you want. Professional architectural services cannot be replaced when it comes to building a home, so the matter is just to choose the one that suits you.
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.