What mistakes should I avoid with visas, immigration and long-stay planning?

Visa and entry conditions depend on nationality and purpose and can change. Use Thai government or immigration information and avoid treating social-media advice as legal authority. Avoid relying on an old timetable, assuming every driver follows the same route, or committing money before understanding the terms. Keep screenshots, receipts and enough backup cash or data to change plans. Immigration note: Entry and extension rules depend on nationality and purpose and can change. Check current Thai government or immigration requirements before relying on an older answer.