This book isn't going to hold your hand as you progress with your tulpa. This is a deliberate choice. The authors believe that merely stating things is just not enough and you must experience the progress as it happens; this makes it a system with a feedback loop. This book will point out the road, but not the exact way to walk it.
It often beneficial to take some precepts to enforce the practice. While we do not require readers to take any precepts, we will highlight a few points that are important to understand.
You may wonder why no other guide mentions any prerequisites like these. As practice shows, it is possible to create a tulpa without following one or even all the rules. The authors strongly believe in that tulpas should be allowed to have free will, which includes a freedom of decisions that the tulpa makes. The precepts help you to calm the mind. They enable the mind to focus quicker. They teach you to respect the tulpa from the very beginning. They will make your progress more smooth.
The ideas written here may sound familiar if you are aware of the five precepts concept from buddhism. Mind that the ideas here carry no religious subtext.
Abstain from killing. A tulpa is not a toy. There is a point in tulpa's life when it can already feel emotions like hatred or feel imposed sensations like pain. The tulpa would still be unable to sustain itself and will rely on the host to keep its consciousness from disappearing. This is the time when a tulpa can be killed or dissipated in an easy way (for the host) while it will experience the related effort and negative emotions. If you are not ready to continue this experiment, please do not start it.
Abstain from taking what is not given. Tulpas often want to communicate with others, doing this by various means: a host can proxy the words, the tulpa can take control of the body or parts of it. Sometimes hosts might want to "role play" the tulpa without its consent, maybe with no ill will in mind, just for some entertainment. Do not steal tulpa's identity and respect it as you respect yourself. The host's personality is overwhelming, and it could be easy to force a tulpa to think that host's opinion on something is ultimately better. Do not force your decisions over the tulpa, even if it's something as simple as its imaginary clothing.
Avoid sexual misconduct. There is nothing wrong with having sex for either a host or a tulpa. Sex is one of natural body desires that are hard to fight against. The important part here is "misconduct". Can you be sure that what you want is same for tulpa? It is not that easy to distinguish the feeling origin in the very beginning; thus, it's better to abstain from things that can emotionally hurt a tulpa. Whatever you do, you must be sure that there's a consensus from the tulpa.
Abstain from false speech. Humans often lie to themselves as they want to see things better than they are. Think about all the things you've read about in the preface. Are you happy with them? Are you going to commit to them? Are you honestly going to commit to them? A tulpa will live in the same brain, but hosts tend to communicate with tulpas as like they are different physical people; this includes occasional lying to tulpas. The thing is, tulpas can follow the thought and see the original intent. Don't lie to a tulpa; it will never work as expected.
Abstain from alcohol and other brain-affecting chemicals. The practice will require you to work hard. Achieving a focus sufficient enough to create a tulpa is hard; achieving a focus sufficient enough to live in harmony with a tulpa is magnitude harder. Alcohol or other brain-affecting chemicals (including weed) destroy that focus of the mind. Applied to the tulpa creation, this precept means that you should not try to modify your experiences. You must meet the practice with an open and clear mind. If you get some progress while being drunk, you might relate that progress to your condition. Likewise, a spontaneous hallucination from marijuana intake might be confused for a tulpa. Either of those forces you to seek more of the mind-clouding experiences, losing your progress in the initial goal.
The life with a tulpa becomes harder as a number of trade-offs doubles. Over the time you will realize that a tulpa is a partner in life, experiencing it on nearly equal terms. It is just not right to force tulpa to experience life in lesser amount because you feel like attending to other needs. This is a shared journey. Don't think of a tulpa as a passenger on a plane that you fly as a pilot. Tulpa will grow to your second-in-command pilot, and it will learn how to share the responsibility for the flight. Don't hold it back from that, and you will get the best part of living with a tulpa.