Decide how to interpret the tone and attitude of the characters in each scene. The tone that you inflect into your voice can have a significant impact on the way the characters come across.
Determine to whom you are speaking and the circumstances under which you are doing so, which can greatly affect the way you present the words. This is especially important when reading sonnets aloud, since there is no specific guidance about the setting.
Stay aware of the wordplay for which Shakespeare is so well known. When you come across repeated words, alliteration and double entendres, the way you read these words can affect their entire presentation and meaning.
Use the meter of the rhyme as a rough guide for pace and rhythm, especially when the meaning is unclear.
Do a quick initial scan through the passages to find any unfamiliar words, then look up their definitions. While knowing the exact meaning of every word is not necessary, a line's meaning can potentially hinge on one word. Knowing the meaning of that key word will be necessary for giving that line the right inflection and intonation.
Read aloud with gusto and zest, trying to keep in mind the way Shakespeare would have wanted his audiences to hear these words uttered. Give a different voice to each character to make a clear differentiation of the various personas in the work. Use accents if you feel comfortable doing so.
Act it out as you go along. Even if you are reading a sonnet rather than a play, you can still animate the words to an extent. Acting out Shakespeare's works will add another level of depth to your understanding and highlight the subtle nuances of the work.