Love this idea!
Each time someone crosses your Mind today, hold them in prayer for a moment. It will change your life and theirs.
You would be surprised how often you are thinking about the various people in your life. Sometimes the thoughts are positive, sometimes not.
What will transform your experience of them (and by extension, your experience of life) is if you pause just for a split second to picture a prayer around that person. You do not have to pray for anything for them (in fact, we may not always know what is in the best interest to pray for that person). You can hold them in the energy of prayer, though, before moving on to your next thought.
You will be amazed how often you think of people throughout the day and how a second of prayer transforms your state of Being.
Did That Just Happen Blog 
I have actually tried this with my husband’s ex-wife…no, not praying that she would fall off the face of the earth, but that her eyes and heart could be opened to how much she is hurting the kids, and how there is a better way. After 13 years, though, I might have to assume she is beyond the reach of prayer, or simply isn’t open to it. I try to remember to pray for my mom, my husband, and the kids every morning, though.