So far, I have found that the process of doodling had reinforced the prayer topic. Also, the image has tended to stick with me through the day - thereby increasing my prayer activity. It's also an approach to prayer that isn't focussed too much on the words (which can often be feeble), but more on thinking through a few words. It's early days, but it seems to be working for me!
It's also brought my journal to life with colour - which I like!