Keep it Positive in the Garden
What do I mean? Often we'll lay out beds, think about their shapes meticulously, plop them in our yard, then fill them with plants...creating a negative space for our main livable area. This main area becomes leftover space, even though it should be the main focus of our garden. The main space is often the lawn (though it could be a patio or deck too). This is very similar to rooms in your house. Each room has a strong shape with walls that reinforce it.
Try designing this way instead...
1. Identify where you would like your main lawn area.
2. Determine what shape it should be...an oval, square, circle, kidney bean, etc.
3. Keep the bed lines clean and/or in broad strokes (not a lot of small wiggles).
4. Place planting beds and plant materials to reinforce your shape (along the outer edge, not in the middle).
5. Now you have an amazing garden where you can place garden furniture, read a book, have a picnic or play a little croquet.
A couple of thoughts...though the positive garden I'm showing you above is formal, your garden does not have to be. This process works for both formal and informal gardens. Also, your lawn shapes do not have to be totally surrounded by plants. You can place them sparingly to still give the idea of a lawn shape, without totally enclosing it.
In the end, please remember that garden design is about creating space. This space is formed by plants and hardscapes, but you must always remember to create the space first.