The way to help someone is not to critique what makes them smaller, but to encourage what makes them larger. - James Clear

The ultimate form of intrinsic motivation is when a habit becomes part of your identity. It’s one thing to say I’m the type of person who wants this. It’s something very different to say I’m the type of person who is this.

Use the moments of high motivation to make it easier when you have low motivation.

-When you feel like you should exercise, set out your gym clothes and water bottle so it's easier to do the next workout.

-When you feel grateful, buy some Thank You cards so it's easier to write the next Thank You note.

-When you feel the urge to eat healthy, pick a recipe now so you don't have to decide what to make for the next meal.

Use the occasional burst of motivation to make the next habit easier.

An approach that has worked well for me: Friendly, but persistent.