The common wisdom is that once you have settled on a particular spiritual practice you shouldn't go chopping and changing it. By all means add to it from time to time, or experiment with other practices occasionally, but your main discipline should remain constant and regular. Think of spiritual practice in the same way you might think of music practice: it might be fun to have a whole range of instruments to become proficient at but, for true mastery, at some stage you will have to settle on one of them and devote yourself to it. True, from time to time you might pick up another instrument, and even become quite good at playing it, but your main musical discipline remains and the more often you practice it the better.
Spiritual practice is ultimately about dethroning the self. If I have a range of things that I am choosing between as the mood takes me, the self is firmly in charge of my spirituality and my whole regime will be limited. The aim is to conform the self to the shape of my practice, not my practice to the shape of my self.
The main benefits of meditation don't come when you are actually doing it. Sure, there is often a sense of restful stillness and there are the physical rewards that accrue from having at least a short time in the day with no stress and all the systems of my body able to go about their jobs unhindered by my usual ceaseless mental preoccupations. But it's later that the real advantages appear: when my mind seems clearer and my reactions seem less fractured. My Holy Spirit time is 3 in the morning: the time when I lie awake and my best ideas pop out of the ether into consciousness. When I am meditating regularly those lovely sessions at the darkest point of the night are clearer, deeper, stronger, and give me far more practicable ideas.
Meditation requires effort. Sometimes it is easy to start each day in the dark and stillness, but I know that sooner or later the day will come when sitting in my study early in the morning will seem a chore; or that one day soon, after ten minutes on my knees a cup of coffee will seem like a more urgent priority than another half hour of keeping still. It's on those days that my practice will seem to be pure hard work, but paradoxically, it is on those days that it will be effecting the greatest change in me.