Cleaning Up refers to integrating the emotional wounds that all of us carry. This can include negative experiences during childhood, more recent ones, or anything that's nagging you daily. It also entails finding ways to more skillfully deal with emotionally taxing situations, such as, a breakup, stress at work, financial worries, etc. In short, cleaning up refers to being comfortable in our Self. Being okay with "who we are" and accepting ourselves.
Our experience of the world is inherently linked to our experience of ourselves (think back of having a good day vs. a bad day and how much that shapes how you look at the world) and it's thus pretty unfortunate that our society, schooling, and upbringing don't put a lot of focus on our emotions and how we relate to them.
indicating that the earliest years are the most important years across a host of indicators of quality of life, ranging from attained income at adulthood, to levels of happiness, relationship stability and support networks. The earlier, the more important!
This isn't because you start learning math when you're a toddler, but because you learn emotional patterns that define your behavior for the rest of your life. Getting in touch with these patterns and relating to them more skillfully is thus one of the most important things one can do!
Two building blocks of my own cleaning up are Internal Family Systems (IFS) and Art Therapeutic techniques.