Here's a quick look at my initial design (in MS Paint ha) for What's Updog? and how that compares to the game's final layout. These screenshots will likely have spoilers if you want to finish my (short!) game first.
Initial

Final

You can see a lot of the same design elements in the layout of the screens and a clear idea of what items I wanted the player to pick up and where to use them if you look closely. Planning ahead like this to make it clear what the goals of the project were meant I had direction the entire time about what I've completed and what I need to do next which really helped me focus on it over an extended period of time.
I also used a website called Trello to help me organize individual parts of this idea so I could narrow down specific things to work on and what was reliant on what to finish before I could start those parts.
Here's a screenshot from when I was in the middle of dev.

Organization is key for any big project!
