Depending upon your preference & the space available to you, it is possible to mix & match a variety of styles, plants & flowers.
In fact, these days the choice is limited only by your space, budget & imagination! Imagine having a peaceful, zen-like corner complete with Japanese style gravel & burbling water feature, separated by a Japanese style bridge from a formal box hedged, rose garden.
Your Rose garden that is filled with a combination of sweet, delicately scented, old fashioned Tea Roses as well as the more modern, unusually hued blooms.
Through a sculpted arch in the box hedging you could wander into your favourite Herb garden area which abounds with the sight & scents of Basil, Thyme, Rosemary, Mint & Sage not to mention Lavender & Parsley, Dill & Chives.
Near the doorway, perhaps you could cultivate a scented Jasmine to waft it's heady scent in the evenings, & a flower bed filled with the most glorious profusion of bedding plants such as Petunias, Primulas & Nicotiana.
Flower beds can actually be kept fresh all year round with a little extra planning & work so that you never have to worry about that winter let down where everything looks so bleak.
Spring bulbs such as Daffodils, Tulips, Irises can give way to Petunias & Nicotiana in the summer.
Asters are hardy autumnal plants & in winter there are Amaryllis & Hyacinth along with Winter jasmine to cheer you.
Plants can even be chosen for their attraction to local wildlife such as Buddleia which is particularly attractive to butterflies.
If space is short for you, bedding plants & herbs can be grown in containers as can small shrubs with the right care & attention.
These can add a huge amount of charm to a small courtyard or balcony even.
Even if you don't have a garden at all, it is possible to create a peaceful indoor retreat where you can be adventurous in growing the more exotic plants such as Orchids amidst almost any other greenery of your choice.