Hello
First: Take a Look at the Tags
If you place the low-sun plants in full-sun gardens, you will encounter problems. The first step to a successful garden seems simple, but many people ignore the tags that come in plants. Read them. They are very helpful. Not only do the tags indicate how much sunlight a given plant should get, but they also indicate how frequently the plants need to be watered, how large the plants will become, and even whether or not they like their root system to be in tight quarters (ie. Plant them in the basket.) or free to roam.
Second: Select Your Soil
Before you break ground, make sure you start things right. Having healthy soil is every bit as important as having healthy plants to put into said soil. Spending a few extra dollars on good earth and topsoil can make the difference between a green thumb and a muddy thumb caused by removing all your dead or dying plants. In a lot of new housing areas, the soil beneath the sod is less than desirable. Take the time to break up the soil and evaluate the nature of what you have to work with. If you are starting a new garden, chances are you will need to dig down a few inches to break up the dirt and make sure there is not a solid layer of clay beneath the surface.
Third: Plan Your Patch
Keep the plants in their pots and lay them out across your garden so you can plan your creation. Keep in mind how big plants can get (you should have already looked at the tags) and space them out accordingly. Also, note any rain drainage that may interfere with plant health and make sure to not plant any non-water loving plants in the path of a gutter. Rearrange the plants until you are happy with the lay out , and then it is finally time to actually stick them in the ground.
Thanks