TONE

For example, the tone could be suspenseful, because the author holds back certain information to create this feeling.
Tone is also generally thought of as describing the work as a whole, rather than a particular section.
How do you create tone in your writing?
It helps to decide what kind of tone you want. Often it depends on the genre. If its a mystery novel, then the tone should be suspenseful, if its a romance novel then its likely that you'll want a certain amount of sexual tension. It's often more the plot than the actual word choice that creates this tone, as the plot generally builds up to a climax that reveals it.
MOOD

How do you create mood in your writing?
While tone is often created using plot devices, mood comes more from word choice and sentence structure. Mood can be created in descriptions of the surroundings, feelings of the characters and actions that take place. Choosing appropriate words for different events will create the mood that is right for a particular scene.
ATMOSPHERE

For example:
"I shivered as I walked through the dim hallway. The hairs on the back of my neck stood on end and I hurried my pace to get away from the frowning portraits gazing down at me."
invokes an atmosphere of nervousness in the writing, which is what the character is feeling.
How do you create atmosphere in your writing?
Atmosphere is about understanding character feelings and getting in their head. It is often most effective for 1st person and 3rd person limited POVs, but as long as your reader can have a relationship with the characters, and feel their pain and joy, then atmosphere can be created. For the most part, atmosphere is about choosing the correct emotions that go with a certain character and the situation they are in. It could be best to concentrate on one characters feelings per scene, rather than trying to cover everyones, because otherwise the atmosphere becomes diluted and is harder to relate to.
VOICE

It's a little hard to explain, but about.com has done a reasonable job:
"Voice is the author's style, the quality that makes his or her writing unique, and which conveys the author's attitude, personality and character."
In my view, voice combines, tone, mood, atmosphere and style to create an overall 'feel' in your writing, which generally translates across all pieces of work.
For example, Dean Koontz has written may books, all with different styles, moods and tones, but the way he combines them is distinctive, and it is easy to know that he has written any one of his books, even if one is written in first person, and another in third.
How do you get 'voice' in your writing?
Voice tends to emerge naturally in writing. They more you write, the closer you will come to discovering it. A lot of it comes down to word choice and sentence structure. Shorter words and sentences create a more abrupt voice, and when combined with particular moods and tones, it becomes quite distinctive.
Sometimes however, it helps to try and define possible aspects of your voice. For example, I believe that my voice tends to have a self-depricating edge to it that translates into a sarcastic kind of humour. I takes a lot of writing (and reading your own work) to discover this, and it can only be done by letting it emerge naturally, without worrying about it.
The most important thing to remember with voice is not to let other's opinions on your work sway you. If someone says that your work could be "funnier", but your voice isn't naturally humourous, forcing it into your writing won't work. Once you begin to discover aspects of your voice however, it is easier to manipulate them, and use them to your advantage.
















