[Porsche-O-Phile]

Residential is tricky - very often you deal with fickle clients who really don't know what they want, think they do and expect endless revisions as they waffle and change directions. That said, there are pitfalls to dealing with commercial clients too but keep in mind that you will work better with your architect if (1) you can communicate your expectations clearly and succinctly (give him or her enough information to develop a design that suits you) and (2) the architect is a good listener. Most are, some aren't.

I usually negotiate a lump-sum fee with specific deliverables and deviations are handled hourly. Keep in mind you're not just buying the architect's stamp but his/her knowledge, experience, training and that of his entire consultant team. You're buying the services of (potentially) a structural engineer, MEP engineer(s), landscape architect, civil engineer, energy modeler, etc... (possibilities are endless depending on specifics). The architect needs to coordinate and direct all those disciplines and focus their efforts into a coherent and biddable package that also complies with all code requirements, best practices, etc. there is no "one size fits all" solution despite what the "house plans here" books say. They (or prototypes, often used in commercial work) always require adaptation, tweaking and refinement, and that costs money - you'll either pay the architect to get it sorted out ahead of time or you'll pay the contractor to sort it out via change order in the field, but you'll pay for it.

Also, definitely get a sense of how involved the architect is with C.A. (Construction Administration). The better ones will do several field visits at key points during construction, take an active role in overseeing construction and keep up a good working relationship with the contractor. If a particular architect comes off as an "ivory tower" type, be wary - there are ALWAYS issues that come up in the field (no matter how good they are or how much effort is put into the design) and it requires a certain attitude and personality to get those issues resolved quickly, efficiently and inexpensively with consideration for all parties' needs.

I'll make the same offer as Katch - if you want to send me an email with any questions or whatever, we can discuss any specific concerns you have, what you can expect, questions to ask, etc.

Best of luck!