According to dermatologists you
always want to shave "with the grain" so to speak...or ear to jaw as you say. (However that only covers your cheeks/jaw/sideburns. Your whiskers can go a few different directions in various parts of your face.)
I try to keep it simple by having a goatee. So I don't have to scrape a sharp razor around my chin and lips and nose. Just down the sides and then my neck under my chin.
I've come to discover however, that there's no real easy way out. This damned goatee takes as much if not more time to keep trimmed and groomed.
Another question might be; single blade or double blade (or more)?
I like a single. A double blade grabs too much. It's uncomfortable and too easy to nick. And those triple blades...geeez, it only takes one swipe with those and you're already through the flesh and hitting bone.
Then there's; electric or blade?
For a brief time I thought electric shavers were just grand. Then I read a completely informative scientific study of the two compared. After seeing some electron microscope close ups of whiskers shaved with both methods, there simply is
no choice. Razor-blade shave left whiskers cleanly cut, uniform, and surrounding skin seemed unharmed. But the electric shaven close ups were downright scary. The whiskers were uneven. None were cleanly sliced or cut, they all looked broken with rough or jagged tops. And much of whisker dust created seemed to end up logded between the hair shaft and the skin. And just washing your face doesn't get it. Seemed kinda unsanitary on top of everything else.
So that's my story...single blade, shave with the grain, good to go.