How does Shakespeare use language to portray the fairies within A Midsummer Night's Dream?

Shakespeare uses rich, lyrical imagery in A Midsummer's Night Dream to accentuate the differences between the magical fairies and mere mortals. He has to employ poetic language to do this, because the fairies inevitability would have been played by humans. All the same, Shakespeare asks us to suspend our disbelief and use our imaginations to see the fairies as he does, mustering all his powers of description and using poetry to seduce us into seeing what his mind's eye sees.

In Act II, scene 1, for example, a fairy uses rhyming verse--brier/fire, queen/green, where/sphere-- to describes the fanciful world of the fairy kingdom, in which the fairies, who can fly, traverse the earth faster than the moon can orbit it and fly through flood and fire. The spots or freckles on the flowers are fairy rubies, which give the flowers their sweet scent:

Thorough flood, thorough fire.

I do wander everywhere

Swifter than the moon’s sphere ...

Those be rubies, fairy favors.

In those freckles live their savors.

Shakespeare also communicates that the fairies are often tiny, describing how the "little elves [fairies]" hide in acorn shells when Oberon is angry:

Creep into acorn cups and hide them there.

This vivid image of frightened fairies cowering in acorn shells conveys more forcefully to us how tiny the fairies are than simply saying they are small. 

Fairies can cause mischief that upset humans and this too is conveyed in rhyme and using rich images that paint a word picture: fairies sometimes steal (skim) the cream from the milk and frustrate housewives by preventing their milk from turning to butter:

Skim milk, and sometimes labor in the quern

And bootless make the breathless housewife churn

Bootless and breathless both begin with "b," creating alliteration in this line. Playgoers can visualize the breathless housewife churning and churning, her hard labor coming to nothing because of fairy mischief.

These are just a few examples of Shakespeare's lush imagery around the fairies, and I would advise looking in acts two and three, scenes one and two of both acts, for more of Shakespeare's description of these magical creatures who can fly off to sit by the river Ganges in India before returning home to England in the same day, who can fit into acorns and flowers and who flit about doing good and ill to humans. The queen and king of the fairies even influence the weather with their moods, which is richly described.