The Calm Mind
An important part of successful practice is an ability to sharpen the focus of the mind. The best way to do that is to add meditation exercises to the everyday practice. It is crucial to keep those exercises neutral; they should not focus on tulpas specifically. The point of them is to experience a better life by training the mind to stay more present.
Meditation is often considered to be a spiritual practice, or something you need to prepare for: burn some essence, sit down in lotus pose, use prayer beads. While some meditation practices do indeed use any and all from this list, the mindfulness meditation is very simple and does not require any special instruments.
Why is it important to be mindful, when it comes to creating a tulpa? When you don't know how to observe your personal thoughts, the mind can look like a busy highway intersection. Lots of cars are moving in different directions, someone speeding, someone drives slow, trying to find the proper exit. Imagine how hard would it to be to pinpoint a single passenger in one of the cars, track them moving through the highway.
The most important part of the tulpa creation practice is to train the mind to be sharp, attentive. This skill spans well beyond tulpas, allowing both them and hosts to live a better life. Inherently, all guides get to the same universal thing: they teach how to focus the mind through various practices, sometimes never actually explaining that the focus is the primary part of the process.
It often happens that the mind isn't calm. Instead, it's agitated, wandering from one thing to another. Is it a good state to work on a tulpa? Yes. Consider the activity as a greater challenge you need to try and overcome. No matter if you have just meditated in a quiet place for an hour, commuted in a busy environment, sitting in a class or trying to grab a lunch --- all those times are great opportunities to focus. Focus on the thing you are doing first, on the senses. Come to the realization about your actions, live consciously. And bring your yet-to-be tulpa into that experience. Share it. Provide something to examine, be it a smell of subway or the touch of bamboo food sticks. Work diligently. Work hard. Every moment you are present in your life is a time to can make a tulpa present too. When the tulpa is present and exposed to senses, it is the best time for it to grow as a personality.