Using Aegis of Zeonia quickly followed by Heartseeker Strike can devastate your enemies.
Using Spear Shot frequently in a battle, along with Attack Speed items, can help defensively by charging Aegis Protection.
Using Grand Skyfall to assist your allies across the map can quickly turn the tides of battle, putting your allies at an advantage.
Keeping yourself hidden in brush can make it harder for Pantheon to target you with Grand Skyfall.
Watch out for when Pantheon has a stunning or snaring partner in lane with him (example: Morgana, Sion) as he can cause devastating damage with his Heartseeker Strike.
Pantheon's Aegis Protection shield will block a single champion basic attack or turret shot, but he's vulnerable until he brings it back up again by attacking or using abilities.