Speak in a “conversation” voice. Use punctuation to create a flow. (consider the dash, semicolon, brackets or purposeful fragments to create rhythm and direct your reader)
Pick words for meaning, sound (alliteration), imagery, sensory and connotative reasons. Drive your sentences w/ strong action verbs (avoid overuse of “to be”).
Word choice, sentence length and rhythm help create voice.
Create small moments in your writing that stand out for their use of poetic techniques (repetition, sensory language, figurative language, etc)
Analogies, similes and metaphors can be powerful, but avoid overused comparisons (My love is like a red rose; I have butterflies in my stomach; my heart sank like a rock, etc.) We have heard them all. Consider unique comparisons to create more interesting writing: My palm grazed the cactus couch with caution. (Why palm and not hand? Why caution instead of trepidation? What is evoked through the use of cactus?)
Don’t always feel like you have to begin at the beginning. Start in the middle. Begin at the end. Playing with sequencing can build suspense and create a more dynamic story; just be careful that transitions for flashbacks and anecdotes are smooth and clearly lead the reader through the puzzle.
The following resources were used to create the above tips. Below are links to the original sites for more in-depth explanations:
The 5 keys to writing persuasive sentences for busy readers