We tend to think of this teaching on kamma as being about past lives and future lives, and really irrelevant for our practice. But the whole thrust of the teaching is, “What are you doing right now?”

"This teaching on kamma: We tend to think of it as being a teaching about past lives and future lives, and really irrelevant for our practice. But the whole thrust of the teaching is, “What are you doing right now?” Or as the Buddha says in one of his questions for daily reflection, “What have I become as days and nights fly past?” Look at what kind of person you’re becoming, given the habits you’ve been picking up, the habits that you’ve been training yourself in — regardless of whether you consciously regard yourself as being in training in that particular habit. A habit of laziness, a habit of carelessness: We don’t think of ourselves as training ourselves in those directions, but if it’s a choice that you keep making over and over and over again, that’s the training you’re giving yourself. So ask yourself: “What kind of training am I giving myself right now, right now?” What kind of training would you like to give yourself in the best of all possible worlds? Well, do that. That’s how you make this the best of all possible worlds. You can’t wait for the conditions around you to become ideal on their own. But you can make a difference in what you’re deciding to do right now."

~ Thanissaro Bhikkhu "Self-starting"