I think it's helpful to write out your primary goals and sub-goals. There are so many exciting ideas out there, that it becomes easy to forget what's already been decided, or how a new idea fits into the overall plan. It also helps to draw out a map of your property and use it to brainstorm these ideas. The
permaculture zoning concept is very helpful for figuring out infrastructure.
In the beginning, my husband and I wrote out a primary goal (for example, ours is to be as self-sufficient as we are able), and listed everything we wanted to accomplish (gardens, orchards, food forest, livestock,
water catchment, etc.) Then, we sat down with our map and tried to visualize and prioritize. We ended up with a rough map of where everything would go on the homestead, and a tentative list of steps to get there. Every time a new idea comes up, we see how it fits into our goals and plans. Periodically, we re-evaluate and update. This has worked well for us, and, I think, saved some frustration here and there.