In the most basic sense, when we refer to right effort, we are referring to the effort to be mindful. But we need to remember that one moment of mindfulness by itself is not difficult to achieve. We simply need to bring our minds to what we are doing right now. What is difficult to achieve, is a continuous stream of mindfulness without any breaks.
For a beginner, this kind of continuous mindfulness cannot be achieved outside of a retreat setting. Right effort therefore boils down to the effort required to attend a meditation retreat. Building on the momentum created by the act of prioritizing our meditation practice, we can then move on to the effort required to sustain our attention in the present moment.
There are various kinds of effort that we need to apply in order to arrange a retreat for ourselves. However the most important decision we need to make is the decision to prioritize meditation practice over our worldly material pursuits. This is not a trivial decision to make because we have been trained to prioritize material well being over virtually any other pursuit.
But if we honestly assess our lives and we can see that our spiritual side has been under-nurtured, a meditation retreat is quite a reasonable use of our time. Right effort in this sense becomes the effort to become aware of the state and trajectory of our lives and whether it is satisfactory or not. If we know that there is another path we need to be on, we should not hesitate to devote the necessary time to make that a reality. The rewards from bringing mindfulness into our daily lives will more than significantly outweigh the costs.