well, I use Gillete Mach 3 Razor on my face (although I've been told a single blade is better) This seems to get all my hair in one stroke instead of several strokes with a single blade razor ... For years I shaved up (against the grain) b/c it made my face smoother for longer .. but I always broke out terribly after I shaved ... now I shave down (with the hair) and my post shaving breakouts have ceased all together ... you don't get as close of a shave this way and you have to shave more often (every other day 4 me) .. but it is so much nicer for your face
I use a shave gel to shave with .. and by FAR the best one for the job is Aveeno Theraputic Shave Gel ... it has oatmeal to sooth your face and is fragrance free and color free and doesn't sting at all ... kinda pricey at $5.00 a can but if you have sensitive skin this is the way to go !
Any kind of aftershave in my opinion is no good b/c they have way too much alcohol, menthol, ect.
As far as AHA and BHA go ... Paula Begoun says it's a no no after shaving ... but using PC 1% BHA lotion for me has caused no problems.. it has anti - irritants in it and feels really nice on my face ... I would say any strong AHA or BHA should be avoided after shaving ... do you use BP ? A nice, gentle strength BP (2.5 % or 5 %) works good for me too b/c shaving leaves your face prone to bacteria and BP will kill it.
Also, I now wash my face after shaving ... seems to help more with breakouts ... and I use a gentle scrub (my personal fav. is DDF Acne Scrub with 2.5 % BP) TWICE a week to help get off the flaky dead skin which causes ingrown hairs and razor bumps for me ... and those tend to develop into zits ...
Hope all this helps