Budgeting without having clear business goals for the next year. The budget becomes purely a formality without generating any benefit to the company.
Budgeting based on last year's indicators. This type of budgeting is very popular and may seem attractive but is also very dangerous. Instead of thinking about what might change next year old trends are brought into in the future. It may be good during a stable situation and for consistent growth, but certainly not in these changing times.