Leaving a Paper Trail
When you're getting ready to start a big project, it's a good idea to get something down on paper. This will help you clarify your goals, keep track of your ideas, and provide documentation of the whole process for future analysis.
You may want to start with a brainstorm: just write down all your ideas and fantasies without censoring yourself. You can pick through to find the realistic stuff later. Do you like lists? Make lists of goal, materials, plants, etc. If that's too linear for you, try drawing circles of all sizes on a piece of paper. In the largest circle write the crux of the project. Smaller circles are bite-size chunks of the biggest circle, ranked in importance by circle size. See my example where I've made a conceptual map of a turtle habitat installation project.
Or do something totally different involving Venn diagrams and flow charts, if that suits your brain.
Eventually you might want to move on to maps that represent real space on your site. If your project involves planting lots of trees for example, a to-scale map will help with proper spacing. A copy of the map can be labeled with each variety planted, and be filed away to serve as a record. (In the future you will be happy that you did this, believe me!) It's also great to have maps to whip out when the salesperson at the garden center starts interrogating you.
Visual records and representations can be as intricate as you want, or as you are able to make. Or they can be penciled lists and hand drawn sketches, whatever suits you and your project best. Sometimes you just have to see what emerges. Here's my model of the turtle habitat. Doesn't it inspire you to come visit and help me hand dig it?