I am probably a bit of an interloper here as I haven't seen any forum comments from UK members.
My garden is on the Isle of Anglesey which lies to the north west of the Welsh coast. It is a semi-woodland garden that I came to in 2005 when it was largely derelict.
This sort of gardening is as far away from formal as you are likely to get in a small private site. I have had to learn to allow nature to have it's way in more places than I have mine.
Most of the site is OK for trees and I have added to the many ash trees (the area used to be an ash forest hundreds of years ago) with oak, horse chestnut, willow and birch.
Not to be completely outdone, I have a small area that has been retrieved from an adjacent field in which I have made a raised bed for roses and an accompaniment of other small infill plants.
Much of the planting that I have done is in such raised beds as it is the only way to reduce invading plants, or at least keep them under control.