The first step is the Natural Planning Model. This will lead to Project Support Material, which might include notes, references, resources, shopping lists, et cetera. People who use powerful list tools like Omnifocus may seek to put a lot of this into their list tool, but other people do well with paper for everything. Some people put one big project on their project list, while others list the big subprojects. The project list is reviewed in the weekly review, which drives you to the support material. You make sure you have good next actions on your next action lists to drive the project forward. Although only real, doable next actions go on those lists, your support material may contain possible future actions. You want to be able to quickly react to changes. For example, you take the tile up in the laundry room, and find out you need to replace the subfloor too.
This may seem a bit non-prescriptive, but there Is tremendous variety in projects, and the people who do the projects use different tools and have different approaches and preferences. However, the Natural Planning Model accommodates them all.