I have a flexible work schedule that can accommodate meetings at odd hours and overseas time zones.
As for payment terms, these include setting a payment schedule tied to the achievement of mutually agreed milestones (i.e. completion of market research, approval of financial model) which vary on a project by project basis. I never expect to receive payments until the client has approved work-to date. Likewise, my clients never holdback 100% until final completion.
I communicate with my clients via landline, mobile, conference calls and video conferencing.