have you tried squirting just a couple of drops so it runs down the pin, then when you push it in those tiny drops act as lubricant?. it works. just point the pin straight up squeeze a couple of drops and turn the syringe as they dribble down the pin, coats it in oil to aid penetration. sounds oddly sexual, but hey, if you do it right pinning can be fun too.

oh, yeah just to add to that, your pain receptors on your skin are actually a couple of mm apart, just lightly touch the needle to your skin where you're gonna jab, if you get a stinging pain you're right on a receptor. move a mm or so and repeat. you should get a dull sensation or nothing at all, that's the spot. something to try anyway.