The items most accessible in our environment often determine what we do in a given moment.
If there are potato chips on the counter, I will likely eat them. If the phone is my pocket, I will likely check it. If the TV is on, I will likely watch it.
We can exploit this by making the important things easier to access. For example, put fruits and vegetables in a visible location to eat healthier. Carry the book you want to read. Lay out supplies on the desk to encourage more creative work.
Conversely, we can increase the barrier for the things we want less of. For example, charge electronic devices in another room. Remove an overused app from the homepage. Hide the chocolate chip cookies behind the cabbage.
Changing the environment alone doesn’t determine whether we do something or not, but it has a huge influence.