I am posting a Design Your Own Garden course here I realise....
This is a checklist I devised to go through with clients who commission a garden design. (Previous posts under Simply Grow on sidebar)
Which of these features would you want or need?
Extra storage for bikes/canoes etc
You may like to make a garden file with your answers to the questions (there are more to come).
Photographs of your garden as it is now will be helpful...not 'arty' photographs just a warts-and-all record of every part of it.