Depending on the project, we can provide "not-to-exceed" quotes based on hourly rates, which will give a good sense of what it will take. This is like a fixed price, except that it will come in *under* budget without the unused portion being due. We can also provide estimates on smaller tasks, on a similar basis.
We also work with retainer agreements and discounted blocks of hours - a tiered rate structure - allowing clients to book time with us in advance. This helps our clients plan their budgets, and it helps us serve clients better, too.