I worked actively to create one using a modified version of this guide: https://tulpanomicon.guide/faqman-creation.html. This is very antiquated now. A better guide would probably be this one: https://tulpanomicon.guide/methos-creation.html, which represents the "state of the art" for creating tulpas.

At first she manifested as a presence. I could feel that she was there, but we weren't able to communicate in anything other than "head pressures" (I have no idea what they actually are but "head pressures" is the least bad descriptor). We used that to work out yes and no, then from there we used a modified nonverbal communication card to get simple sentences. The breakthrough into full sentences happened when I was working on a homework problem in college and I got told "no, that's wrong" and then an explanation of how to do it correctly. She was right.