Make proper plan
The best laid gardens have been thought up much before the ground was broken to sink in the foundation to the premise. Then it would be appropriate to think of the direction of the sun and the wind flow to try and make sense of what has been the greater plan. Planning is everything to gardening and laying out the gardens as well. This avoids unnecessary clearing of plants and also the ground can be prepared to perfection.
Poor planning is often double or more of the efforts to establish the same garden. Often it would mean rework on a grand scale most of the time.
Match the garden to the architecture
Imagine the Taj Mahal without the Mogul gardens?? That is how important is architecture to the layout of the garden. The garden space must match the architecture plans and come to represent what the whole layout is aiming to be for the most part. Gardens are meant to complement the buildings that they surround or beautify for the most parts. Instances of a bad match of garden would mean that the work would have to be redone from time to time to achieve near acceptable results.
Keep the scale in sight
The scale here applies to the garden as a whole and the smaller items like the size of the flower beds and the likes. It is mostly a matter of proportions more than anything else. If the entrance to a garden is rather big and arched, then there needs to be a feature to match the garden layout to the entrance else the sight would be ungainly and uncomfortable to say the least.
If the aim of the garden is to provide a set of flowery gardens to look to then, care must be taken to match the bloom times of the flowers in the garden. That is the garden should not be just with flowers that bloom all together or at the same season. It is possible to find garden flowers that bloom during the winters as well.
An experienced gardener would be able to understand the climate and the relation that it has to the bloom times. It is then a matter of mostly matching the blooms to the proper seasons and no more.
Like people plants and trees have a productive life and a death eventually. The aim must be to keep the plant life diverse enough to be able to have a green cover throughout the life of the garden and beyond. By planting trees that are huge and with large canopies, it is possible to extend the green cover to beyond a few decades at least. It is the proactive gardener and garden setter that allow the most potential to be realized from a garden as the case might be.