I personally have no clue. But I know my husband does

 

Very carefully! :)

 

Oh, you can do it! It's fun!

Release the "P" into the "F". It's sort of like starting your "f" with your upper and lower lips together, instead of lower-lip to upper-teeth.

You're used to your "P"s releasing with an puff of air, since that's what they do in English when a vowel comes next. But you can do non-plosive "P"s": you do them in english words that start pl--,

Have you ever worked on syllables that start with ts-, like tsar? It's kind of the same principle. T is a "stop" sound like P (it stops the air flow when you make it); S is a fricative like F (air flow moves through, but through friction).

The pf- one is harder than ts- since usually your p- and f-- are more different in their lip to lip and lip to teeth contact points. t-- and s-- have the same or nearly the same tongue to roof-of-mouth contact point.

you're awesome for even caring to figure it out, btw.