When you are considering different features for your lawn and gardens, it is important to understand that each element is part of the whole, thus proportion is a principle to keep in mind. You may have a small lawn, or you may have a large garden, but each element needs to match in scale and proportion to the surrounding pieces.
You should keep in mind these three aspects of measurement when picking out plants and other objects to place into your lawn: length, width/breadth and height/depth. Noting these general measurements will help you avoid picking out disproportioned things for your yard. For example, you would want to avoid setting a large fountain in the middle of a small garden, just as you would want to avoid setting a small rock alone in a widespread lawn. The first would be a mistake because the fountain would go beyond being a focal point to being a distraction, taking an onlooker's attention away from any other aspects of the garden. The second would be a mistake because the small rock, without any other similar elements nearby, would probably go unnoticed.
As much as you want to make sure nothing is drastically out of proportion or off-scale to the general theme of your lawn or garden, you also want to stray away from making your garden contain the same sized features all in a row. This would be boring and signal a lack of imagination and creativity on your part.
Read on to get an understanding of what landscape grouping means, and how to apply it to your lawn or garden.