Tip 1: Give your character an unusual feature, habit or saying, or liken them to something, such as an animal. You might say he was strong and bovine, then comment on the veins standing out on his neck. Later he might stamp his foot and bellow in rage. Simply by mentioning an unusual feature you are creating a mental image for your readers.
Tip 2: Ensure that the reader knows who is telling the story – whose viewpoint is put across – as early as possible in each scene. If your character has internal dialogue/thoughts, then the reader will know the story is being told by that character.
Tip 3: Mention character names a little more frequently early in the story. Choose names that suit the era and place the person is born. Use the internet to find the most common name for each era – you can even find lists of names for fantasy or science fiction characters. Be sure to make the names pronounceable (readers like to ‘say’ the names in their heads). Avoid too many names in the same story that begin with the same letter.
Tip 4: Give an early and brief description of your character. Don’t over-describe the character at the beginning, however give the reader some defining features so they can form an image in their mind. Give the reader enough for a 'first impression' in looks and personality.
Tip 5: Whose story is it? If one of your secondary characters appeals to you more, and is 'taking over the story', you might have chosen the wrong protagonist. Or you might decide to tell the story with multiple points of view. Some novels contain many characters’ points of view.
Tip 6: Don't reveal everything about your character in the beginning. Leave room for the character to grow; for the reader to become curious, and for you to get to know him/her. Interesting character information to reveal as the story progresses are dreams, memories, lessons learnt as a child, mistakes make, wishes, regrets, fears, idiosyncrasies, collections, etc.
Tip 7: Know each character's motivation for action. If the reasons for your character's actions and thoughts are not clear to you, the writer, then you will probably find your character doing or saying things that are not believable. Character motivation comes from within – and from the external events that have formed that character over the years. The character's actions will be a result of both internal and external motivation. Give yourself time to really understand your character.
Tip 8: Give your characters inner conflict. Allow your character to be pulled two ways, to explore the options, to make wrong decisions and to sometimes feel despair at having no acceptable options.
Tip 9: Base characters on a combination of people that you know or have met in real life. A character can often be a blend of many people. Feel free to use the stories, backgrounds and character traits of many different people. If you write about something that a real person did, it will come across as authentic.
Tip 10: A character’s dialogue reflects their background, age, education, social status and place of origin. If your character has distinctive dialogue traits, you can almost eliminate the use of speech tags. Think about using favourite words, sayings, nicknames, mispronounced words, etc. for your main characters’ dialogue.
Tip 11: No character is all good or all bad. Give your antagonists some endearing qualities and make your protagonists human enough to make mistakes, have dark secrets or a bad habit.
Tip 12: Dedicate a note-book to your main character. I like the little A-Z ones, then note down everything you can think of about them, from childhood and relatives to the time they appear in your story. You may not use it all, but merely thinking about all aspects of your character will make them stronger in your story-telling.