While motivation matters a lot, evidence suggests that environment might be even more important to succeeding in habit change. This can partly relate to factors outside our individual control, but also to how we design our environments and routines to set ourselves up for success. Of course, making those environmental changes can also be a challenge! For example, I find it easier to exercise when my house is fairly clean, but I also sometimes struggle with cleaning habits.
Mostly, I try to think about smart strategies for environmental design (including using the right tools and routines). Then I remind myself that habit design is an iterative process. Small habit change can lead to small, helpful environmental change, and sometimes finding the right small change to start with is enough to create a positive cascade that ripples out in various direction.
Lots on habit may eventually end up in the spirituality section, too.