How can I find a final approach fix (FAF)?
For precision approaches, the Final Approach Fix (FAF) is defined as one of three points:


A lightning bolt symbol on FAA government approach plates
The (published) glide slope/path intercept point on Jeppesen approach. The glide slope/path symbol depiction starts at the FAF on these plates.
Or, it is the resultant actual point of the glideslope/path intercept when ATC directs a lower-than-published glideslope/path intercept altitude


Since FAA government (NACO) charts answer your question with the depiction of the lightning bolt symbol, your question applies primarily to Jeppesen charts (other chart vendors perhaps as well). Jeppesen charts include the glide slope intercept altitude in the briefing strip near the top of the plate. So, the FAF for precision approaches is the location at which glideslope intercept is to occur when at the lower of either the published or ATC directed altitude.

See the following excerpt from the FAA's Pilot/Controller Glossary:


  FINAL APPROACH FIX− The fix from which the final approach (IFR) to an airport is executed and which identifies the beginning of the final approach segment. It is designated on Government charts by the Maltese Cross symbol for nonprecision approaches and the lightning bolt symbol for precision approaches; or when ATC directs a lower-than-published glideslope/path intercept altitude, it is the resultant actual point of the glideslope/path intercept.


See the following excerpt from Jeppesen's Airway Manual:


  FINAL APPROACH FIX (FAF) — The fix from which the final approach (IFR) to an airport is executed and which identifies the beginning of the final approach segment. It is designated in the profile view of Jeppesen Terminal charts by the Maltese Cross symbol for non-precision approaches and by the glide slope/path intercept point on precision approaches. The glide slope/path symbol starts at the FAF. When ATC directs a lower-than-published Glide Slope/Path Intercept Altitude, it is the resultant actual point of the glide slope/path intercept.