Do you ask your friend to pray for you?
Of course!
There is a familiar Guardian Angel prayer that most Catholics know by heart.
I remember praying it a lot as a child. Not so often now. Unless I am driving in heavy traffic. But I am more like to just pray "Jesus, help me." now.
Um, actually no. If people offer to pray for me I do appreciate them and ask they pray that I'd be a more faithful Christian. If I offer any prayers it's to the effect that I be much more faithful. As far as my needs however, God has and will take care of me.