That's an excellent question, and it's one we cover a lot here on the Expert Center. In fact, Levelset has written extensively about this topic, and I think this resource goes into better detail than I could in this answer: How to File Your Texas Mechanics Lien – A Step by Step Guide to Get You Paid. That article has an entire section on what attachments should be included with Texas mechanics lien claims, and it even has helpful tips on how to fill out the mechanics lien form, itself.
Further, if you're curious about other Texas mechanics lien requirements, Levelset has this resource featuring lien deadlines, what amounts can be claimed, and more: Texas Mechanics Lien Guide and FAQs.
I hope that information is helpful! If you have any clarifying questions, feel free to come back to the Expert Center and ask!