I think as a DPM, especially if you are starting out new without much experience outside of residency - it is somewhat difficult to have a purely surgical practice. This will come with experience and with building your reputation amongst the other healtchare providers. Put it this way, I think the most important aspect is to be able to network and work with everyone - doctors, nurses, allied health professionals, staff, and of course patients.
Second, I think that a doctor who knows the demographics of his/her area and is able to adapt to his patients needs accordingly will be successful. I don't think its necessarily who presecribes "x" number or orthotics, or "x" number of surgeries, etc. A healthy balance is important but understanding your patient's needs is vital. For example, if you have alot of diabetic patients and you can't treat their ulcers or manage their wounds, or even refuse to do routine care - then chances are you won't be too successful. You have to be able to recognize and adjust to these needs appropriately. The beauty of this specialty is that you have an array of clinical aspects to apply in a typical day's work - but you have to be smart in managing your practice as well - investing in your practice is important - the staff, new equipment, treatment options, etc.
Furthermore, I strongly feel that knowing your limitations is very important - i.e. don't risk trying procedures you can't master and ruin your reputation because you are doing great service to your patient by referring him to someone who can.