Look at designs. There are many landscaping books and magazines that can help you design your flower beds, or at least give you an idea of what types of plants and layouts you like. In addition, if you have friends or neighbors who have flower beds you like, ask them how they did it, or ask them to help you design one of your own.
 Know the plants. Don't just choose a bunch of plants based entirely on looks. Different plants and flowers have different requirements in terms of soil, watering, sunlight, and so forth. In addition, some plants spread, which will have an effect on the overall design of your flower bed. Make sure you know the requirements for each plant as you begin your designing so you will be able to plant them in the right spots. Most plant tags will have this information, as well as gardening magazines and books.
 Plant in groups. Plant the same plants together in groups; most often, large blooms in flower beds are the result of several plants grouped together. Plant most of your plants, except for single-stalk flowers like irises or stand-alone plants, in groups of three or more.
 Check height requirements. This is important for a number of reasons; taller plants that hide sun from some of the smaller ones will kill them, and aesthetically it looks more pleasing to organize plants by size. In terms of flower design, there are edgers, which are the flowers in the front of the bed; fillers, those planted in the middle of the bed; and the backdrop plants, or the taller ones that go in the back. You can break this "rule" if you know enough about plant requirements; sometimes it looks nice to break it up a little bit.
 Have a focal point. A focal point is a good way to draw attention to your flower beds. Accents such as a bench, arbor, gate, bird bath, or some type of statue are a beautiful addition to a flower bed. If your garden or flower bed is quite large, you can have more than one focal point and your flower bed will still look balanced.
 Consider symmetry. Balancing your garden by putting certain bushes or flower plants makes it look balanced and nice. This is a more formal approach, so if you want your garden or flower beds to look more like wild flowers or more like a country garden, then you wouldn't want to make everything formal.
 Take color into consideration. Certain colors look better than others, so make sure you like, for example, the look of red and pink together if you plan on planting them next to each other. All one color flower beds can be striking as well.

Remember that the way you design your flower bed is an expression of your own likes and creativity. Just make sure to know the plant's requirements, and from there have fun designing a beautiful flower garden.