The best prayer for anything is the Rosary which is only second to the Holy Mass.
Start your rosary by petitioning for the graces you need, give thanks for what you have, and be contrite for your sins.
Then say the prayers of the rosary.
Try to meditate up on each Hail Mary bead.
*For the First three beads before the first decade:
Bead #1 Meditate Upon Faith
Bead #2 Meditate Upon Hope
Bead #3 Meditate Upon Love
*^^^This is a method I use. I do not see any harm in it but it might not be necessary.
For each decade be sure to meditate upon a certain mystery using one of the sets of mysteries.
Also, have a petition before each decade as well to go along with the mystery.
If you have any more interest in the Rosary I would recommend the Pocket Rosary Guide by Matt Fradd and the Secret of the Rosary by St. Louis-Marie de Montfort. The rosary is one of the most powerful tools God has given us to trust Him, receive His grace, and conquer sin.
Hope this helps!