Many will blame the prayer or their prayer rule when they experience coldness in prayer. Saint Theophan says, "If prayer is going poorly is not the fault of the prayer but the fault of the one who is praying." He points out that it is our haphazardness in our approach to prayer that is the most common problem. For me, this occurs when I am in a hurry. I want to rush through my prayers so I can get on with a busy day. When this happens my prayer become routine and my heart is cold in relation to the words of the prayer and it is no longer prayer. It becomes simply another task for the day.
What do we do when we experience this coldness in prayer? Saint Theophan says simply, "reprimand yourself and threaten yourself with Divine judgment."
When we are in a hurry we are making God secondary in our life. Most of us spend very little time in prayer in relationship to all the other activities of our life. We really do not have any excuse for trying to rush through our daily prayers. We need to shame ourselves for this. No one else can do this for us. Our haste only leads to a compete waste of time. Prayer without feeling is not prayer.
Saint Theophan outlines what some people do in regards to prayer.
They set aside a quarter of an hour for prayer, or half an hour, whatever is more convent for them, and thus adjust their prayer time so that when the clock strikes, whether on the half hour or hour, they will know when it is time to end. While they are at prayer, they do not worry about reading a certain number of prayers, but only that they rise up to the Lord in a worthy manner for the entire set time. Others do this: Once they have established a prayer time for themselves, they find out how many times they can go around the prayer rope during that period... There are others who get so accustomed to praying that the times they spend at prayer are moments of delight for them. It rarely happens that they stand at prayer for a set time only. Instead, they double and triple it. Select whichever method pleases you best. Maintain it without fail... A large part of my daily prayer rule is reciting the Jesus Prayer. For a while I would set a set number of prayers to accomplish my rule. I found myself rushing to complete them in a shorter and shorter time. I even came up with innovative ways to say them faster. I finally realized that I was not praying when I did this. Prayer was not about numbers but about a arm feeling in the heart in an intimate relationship with God. So I changed my practice to one based on a set time. Now I concentrate only on the words of the prayer, my Lord and Creator, and not on how many times I am repeating the prayer. This allows for a varied pace depending on your current state and allows for some spontaneity in your prayers as well.
Reference: The Spiritual Life, pp 287-289