I've found that a belief in the sovereignty of God really enhances my prayer life rather than diminishes it. I can spend more time thanking God and praising Him for who He is. I can also approach God with more confidence because I know that, even if I don't know exactly what to ask for, that our Father will always give us what is best, for:

9 What man is there among you who, when his son asks for a loaf, will give him a stone?
10 "Or if he asks for a fish, he will not give him a snake, will he?
11 "If you then, being evil, know how to give good gifts to your children, how much more will your Father who is in heaven give what is good to those who ask Him!

(Mark 7:9-11)

True godliness is a sincere feeling which loves God as Father as much as it fears and reverences Him as Lord, embraces His righteousness, and dreads offending Him worse than death~ Calvin