Going to the gym twice a week doesn't work. Inevitably, something will come up, causing you to delay it, only to find yourself out of the habit after a while. This is true for any kind of habit.
To make something stick, you need to make it part of your identity. Whether it's learning a new skill, going to the gym, or creating something, do it daily. Only if it becomes part of your identity—something you do every day without needing to make a conscious decision—will it stick beyond the initial excitement period.
To make something part of your life, you need to make it part of who you are. And this requires doing the thing every day.