1) a foregone conclusion

Shakespeare’s Othello (1604) is the source:

But this denoted a foregone conclusion:
‘Tis a shrewd doubt, though it be but a dream.

2) all of a sudden

In The Taming of the Shrew (1596):

Is it possible That love should of a sodaine take such hold? [sodaine was one of many spellings of sudden]

3) apple of my eye

The phrase refers to something or someone that one cherishes above all others.  This goes ALL the way back to The Bible- WOW!  The Bard used it in A Midsummer Night’s Dream:

Flower of this purple dye,

Hit with Cupid’s archery,

Sink in apple of his eye.

4) the be all and end all

This is another of Shakespeare’s inventions (dating back to 1605).  Here’s the reference from Macbeth:

If it were done, when ’tis done, then ’twere well
It were done quickly. If th’ assassination
Could trammel up the consequence, and catch
With his surcease, success: that but this blow
Might be the be-all and the end-all

5) cute as a button

“Cute, charming, attractive, almost always with the connotation of being small, 1868 (from the original 1731 English meaning of acute or clever).” Cute as a button dates back to 1946. Cute and keen were two of the most overused slang words of the late 1920s and 1930s.” From Listening to America by Stuart Berg Flexner

6) fair play

Shakespeare coined this phrase and used it in several of his plays; for example, The Tempest (1610):

Yes, for a score of kingdoms you should wrangle,
And I would call it, fair play.

7) fancy free

From Shakespeare’s A Midsummer Nights Dream (1598):

That very time I saw, but thou couldst not,
Flying between the cold moon and the earth,
Cupid all arm’d: a certain aim he took
At a fair vestal throned by the west,
And loosed his love-shaft smartly from his bow,
As it should pierce a hundred thousand hearts;
But I might see young Cupid’s fiery shaft
Quench’d in the chaste beams of the watery moon,
And the imperial votaress passed on,
In maiden meditation, fancy-free.

8) heart’s content

This phrase is first put into print in Shakespeare’s plays and there’s every reason to believe that he coined it. He used it in at least 2 plays, such as in The Merchant of Venice (1596):

I wish your Ladiship all hearts content.

9) hot-blooded

“Hot-blooded,” or as Shakespeare wrote it ‘hot-bloodied’, first appears in The Merry Wives of Windsor, 1600:

The Windsor bell hath struck twelve; the minute draws on. Now, the hot-bloodied Gods assist me!

10) in a pickle

There are a few references to ill pickles and this pickle in print in the late 16th century.  Shakespeare was one of the first to use in a pickle, in The Tempest (1610):

ALONSO:
And Trinculo is reeling ripe: where should they
Find this grand liquor that hath gilded ’em?
How camest thou in this pickle?

TRINCULO:
I have been in such a pickle since I
saw you last that, I fear me, will never out of
my bones: I shall not fear fly-blowing.

11) I will wear my heart upon my sleeve

From Shakespeare’s Othello (1604), as spoken by Iago:

It is as sure as you are Roderigo,
Were I the Moor, I would not be Iago:
In following him, I follow but myself;
Heaven is my judge, not I for love and duty,
But seeming so, for my peculiar end:
For when my outward action doth demonstrate
The native act and figure of my heart
In compliment extern, ’tis not long after
But I will wear my heart upon my sleeve
For daws to peck at: I am not what I am

 12) in stitches

The phrase was first used by Shakespeare in Twelfth Night (1602):
If you desire the spleen, and will laugh yourself into stitches, follow me. Yond gull Malvolio is turned heathen, a very renegado; for there is no Christian, that means to be saved by believing rightly, can ever believe such impossible passages of grossness. He’s in yellow stockings.

13) lie low

There are many citations of variants of this little phrase dating back to the 13th century. Shakespeare used it in Much Ado About Nothing (1599):
If he could right himself with quarreling,
Some of us would lie low.

14) love is blind

This expression is first found in Chaucer’s Merchant’s Tale, circa 1405:

For loue is blynd alday and may nat see.

It didn’t at that stage become a commonly used phrase and isn’t seen again in print until Shakespeare took it up. It appears in several of his plays, including Two Gentlemen of Verona, Henry V, and in The Merchant Of Venice (1596):

Here, catch this casket; it is worth the pains.
I am glad ’tis night, you do not look on me,
For I am much ashamed of my exchange:
But love is blind and lovers cannot see
The pretty follies that themselves commit;
For if they could, Cupid himself would blush
To see me thus transformed to a boy.

15) makes your hair stand on end

This is first found in Shakespeare’s Hamlet (1602):

I could a tale unfold, whose lightest word would harrow up thy soul, freeze thy young blood, make thy two eyes, like stars, start from their spheres, thy knotted and combined locks to part and each particular hair to stand an end, like quills upon the fretful porpentine [porcupine].