blow job tips?

i need advice on how to give a blow job. i've tried before but i'm an amateur and he deserves better in my opinion. so far i know he doesn't like the whole two hand handjob thing, likes when i suck on it like a popsicle but HOW do i make sure it's lubricated enough?! they say the sloppier the better but my mouth doesn't hold that much saliva and i just get discouraged! should i spit on it or is it disrespectful?