Do not add fuel to the fire.

To get cold feet

You cannot <u><em>have your cake and eat it too</em></u>.

Queer somebody's pitch

His <u><em>oily tongue</em></u> has won him promotion.

To go to each other hammer and tongs

In his youth, he was practically <u><em>rolling in money</em></u>

If you pass this difficult examination, it will be a <u><em>feather in your cap</em></u>.

Pell-mell