Inside a word or at a word end: stopaim (STOHP-im), iompair (UM-pir), leapa, ceap (kyap), rap (rahp).
To pronounce a "p" when the nearest vowel in the word is "e" or "i", bring the lips in close to the teeth and spread the lips slightly, as in a faint smile. Try: pé(pay*), pic (pik), pian (PEE-uhn), péist (pay*sht), Peadar (PAD-uhr), peann (pyoun).
Inside a word or at a word end: impire (IM-pir-e), teipim (TEP-im), scaip (skahp), scléip (shklay*p).
Finally, practice on these two words that have both broad and slender "p", until you can say the word easily and naturally: píopa (PEEP-uh), páipéar (paw*-PAY*-uhr).