head tips and tricks

I've given a few guys head before however I feel like I may not be good at it as non have came in my mouth before. Are you suppose to actually suck on it like an icecream or put it as far back in your throat and keep doing that just putting your mouth over it. I know to suck and kiss the balls and the tip and all that jazz but just the main deal. My mouth also gets very dry so I can't exactly spit on it 
Is there a good position to do it best.