Spend time active forcing as often as you can, and during the day talk to them/pay attention to them, and encourage them to tell you what they think about things
Because you're paying attention to them and putting your focus on growing them, they're getting reinforced in your brain as time goes on until eventually developing autonomy
of course, there's no way for me to know this for sure, but it's what I'm assuming based on the fact that revisiting thoughts/habits makes them stronger forces in your brain, I think that's the same for tulpas
11:26 PM
Talking to them and allowing them to experience your day-to-day life helps them form their own personality/identity, which coupled with autonomy makes them a person