I have been providing consulting services for many years and have developed a number of policies that benefits both the client and my business.
My rates are pretty straight forward. I charge by the hour of work provided, whether at your site or from my own facilties. The rate range is $50 to $100 an hour. The low end of rates are for long term employee like projects. The high end jobs involve unique designs or considerable on site hands on solutions. Travel expenses are paid by the clients when not within the Sacramento service area.
I keep running logs of all activites and will include a copy of the project log with each billing. Typical billing takes place on the first and middle of each month. I expect payments before the next billing without prior arrangements. Delays in payment can cause withholding of services.