Directly ask your supervisor or administrator for funding/reimbursement by following these best practices:
Informally inquire about the possibility. Example: NCTE’s Annual Convention happens this November; it’s the premier professional learning opportunity available for ELA educators. You can learn more about it on this website: convention.ncte.org. Attending is a way for me to meet leading teacher voices, research scholars, and authors to continue my growth in service of students and literacy. Can we find funds to support this important experience for me?
State your case formally and intentionally. Example: Use template. A best practice is to lift up the anticipated impact that attending will have on your practice and that of your colleagues (by presenting back to them key takeaways from the professional learning upon returning), and therefore, on student achievement.
Plan your budget. You can get a very clear picture of exactly how much this event will cost by looking at the Registration and Hotel & Travel pages of the website.
NCTE Convention Scholarship opportunities were also available. The deadline has now passed.
Get creative and use crowdfunding sources to cover registration. The support for getting teachers the professional learning and experiences they deserve is out there—make public your wish to attend and explicitly state your need(s).