What are the general grounds for termination?
1. Just Causes
2. Authorized Causes
What are the grounds for termination under Just Causes? 
1. Serious misconduct
2. Willful disobedience by the employee of the lawful orders of his employer or representative in connection with his work.
3. Gross and habitual neglect by the employee of his duties
4. Fraud or breach of trust by the employee of the trust reposed upon him by his employer or duly authorized representative
5. Commission of a crime or offense against the person of his employer, or any immediate member of his family or his duly authorized representatives
6. Other causes analogous to the foregoing.
What are the grounds for termination under Authorized Causes? 
1. Installation of labor-saving devices
3. Retrenchment to prevent losses
4. Closure and cessation of business
5. Disease or illness 
How much is the separation pay for termination under Authorized Causes?
1. In case of installation of labor-saving devices or redundancy, the worker affected thereby shall be entitled to a separation pay equivalent to at least one (1) month pay or at least one (1) month pay for every year of service, whichever is higher.
2. In case of retrenchment to prevent losses and in cases of closures or cessation of operations of establishment or undertaking not due to serious business losses or financial reverses, the separation pay shall be equivalent to one (1) month pay or at least one-half (1/2) month pay for every year of service, whichever is higher. A fraction of at least six (6) months shall be considered one (1) whole year.
3. In case of disease or illness, separation pay shall be equivalent to at least one (1) month salary or to one-half (1/2) month salary for every year of service, whichever is greater, a fraction of at least six (6) months being considered as one (1) whole year.
What procedure should be observed by the employers in terminating employees for a just cause?
1. Employers shall serve a first written notice to the employees which should contain the specific causes or grounds for termination against them, and a directive that the employees are given the opportunity to submit their written explanation within a reasonable period. This should be construed as a period of at least five (5) calendar days from receipt of the notice to give the employees an opportunity to study the accusation against them, consult a union official or lawyer, gather data and evidence, and decide on the defenses they will raise against the complaint.
Moreover, in order to enable the employees to intelligently prepare their explanation and defenses, the notice should contain a detailed narration of the facts and circumstances that will serve as basis for the charge against the employees. A general description of the charge will not suffice.
Lastly, the notice should specifically mention which company rules, if any, are violated and/or which among the grounds under Art. 282 (now Art. 297 of the Labor Code) is being charged against the employees.
2. Conduct of formal hearing or conference which becomes mandatory only when requested by the employee in writing or substantial evidentiary disputes exist or a company rule or practice requires it, or when similar circumstances justify it.
3. After determining that termination of employment is justified, the employers shall serve the employees a written notice of termination indicating that: (1) all circumstances involving the charge against the employees have been considered; and (2) grounds have been established to justify the severance of their employment.
What procedure should be observed by the employers in terminating employees for an authorized cause? 
1. Service of written notice to the employees specifying the grounds for dismissal at least 30 days before the date of termination.
2. Submission of a copy of the notice to the Regional Office of the Department of Labor (DOLE) where the employer is located at least 30 days before the date of termination.
What is the sanction if the employer failed to observe the procedural due process in terminating an employee?
1. For just causes, the employee shall be entitled to payment of indemnity or nominal damages in a sum of P 30,000.00. 
2. For authorized causes, the employee shall be entitled to payment of indemnity or nominal damages in a sum of P 50,000.00. 
You may email firstname.lastname@example.org for assistance.
See related posts:
"Retrenchment - Laying off employees due to business losses"
You may also refer to the government's official publication of the Labor Code of the Philippines.
 Art. 297 (formerly Art. 282), Labor Code  Art. 298 (formerly Art. 283), Labor Code  Art. 299 (formerly Art. 284), Labor Code  Supra note 2.  Id.  Article 299 (formerly Art. 284), Labor Code
 Supra note 2.