cross your fingers (or keep your fingers crossed) hope that your plans will be successful; trust in good luck.

☞ The gesture of putting your index and middle fingers across each other as a sign of hoping for good luck is a scaled-down version of the Christian one of making the sign of the Cross with your whole hand and arm as a request for divine protection. It is also superstitiously employed when telling a deliberate lie, with the idea of warding off the evil that might be expected to befall a liar. The abbreviated fingers crossed is often used as if as a charm, to keep ill luck at bay.

2014Stuart Ian BurnsFeeling Listless Hopefully 2014 won't include another hernia or anything else which requires an operation, fingers crossed.