There are two ditches on the side of the road of Christian life. One ditch is lawlessness (antinomianism), and on the other side, the ditch of a harsh and hostile legalism that binds spiritual chains around us. Both of these extremes should be avoided always. Yet there is a road to walk if progress in sanctification is to be made, and as the saying goes, to fail to plan is to plan to fail.
Prayer Plan: No one wishes for something introduced only with good intentions, to then become a yoke of slavery on the neck. We must always remember that a failure to hold to a plan strictly does not mean our relationship with God is severed our soured in some way. Our performance is not the basis of our standing before God. The gospel of Christ is. Justification is by grace alone through faith alone in the Person and work of Christ alone.
Having said stressed that and made that very clear, it has to be said that it is very much a good thing to have a plan for prayer.
I read the following article by Mike Riccardi at the Cripplegate website and thought some excellent points were made:
In his classic, Desiring God, John Piper diagnoses that a main hindrance to prayer is our lack of planning. He tells us,
Unless I’m badly mistaken, one of the main reasons so many of God’s children don’t have a significant life of prayer is not so much that we don’t want to, but that we don’t plan to. If you want to take a four-week vacation, you don’t just get up one summer morning and say, “Hey, let’s go today!” You won’t have anything ready. You won’t know where to go. Nothing has been planned.
But that is how many of us treat prayer. We get up day after day and realize that significant times of prayer should be a part of our life, but nothing’s ever ready. We don’t know where to go. Nothing has been planned. No time. No place. No procedure.
And we all know that the opposite of planning is not a wonderful flow of deep, spontaneous experiences in prayer. The opposite of planning is the rut. If you don’t plan a vacation, you will probably stay home and watch TV. The natural, unplanned flow of spiritual life sinks to the lowest ebb of vitality. There is a race to be run and a fight to be fought. If you want renewal in your life of prayer, you must plan to see it.
Justification is a legal court room term defined as the act of God when He declares a person just or righteous in His sight. This takes place the moment a sinner places their trust in the Savior, the Lord Jesus Christ. For the sinner who has faith in Jesus, God pronounces the sentence “I find you not guilty! I reckon (I count, I declare) you righteous in My sight, and you and I are forever at peace with each other. All of your sins were transferred to your sin bearing Substitute, the Lord Jesus Christ, who took the full brunt of My holy wrath for you, and what has been transferred to your account is the righteousness of My Son, who lived not only a sinless life, but a life fully pleasing to Me. This very real righteousness is yours now and forever.” 
One man said he had two horses living inside him; one a beautiful white horse called holiness; the other a dark foreboding horse called covetousness.