First and foremost, build a good system for your place. The first thing you’re going to do is look at your operation, make some goals and plans. That is probably what sets most operations apart from being run of the mill to probably a quality operation.
If you’ve got the goals, you’ve got your plan, then you can start picking out what do if this happens, what to do if that happens. But for gosh sakes keep it as simple as you can because if you get it too complex it overwhelms you...
Drought is only one of the management challenges that ranchers need to plan for. It is important that the decisions you make before, during, and after drought fit into your overall plan. The decisions you make before, during, and after drought should help move you closer to the vision or goals that you have for your ranch.
If you do not already have specific goals, the resources listed here may be helpful. Your county extension or NRCS office, or private consultant, may also be able to help you think through your goals.