What should the post closing trial balance is best prepared from?

The General Ledger provides all the information you need to prepare a Post Closing Trial Balance as well as a Trial Balance, etc.

A post closing trial balance is a trial balance that is prepared "before" accounts are closed out for the accounting period, such as expenses, revenues, etc. Adjusting entries are made to the General Ledger from the Journal entries and then a PCTB is prepared using the information obtained in the Ledger.