I just cut a nail or two a night. I cut while they are laying on the floor sleeping, chewing, acting stupid. My guys are used to me randomly grabbing them and pulling on them, and plain messing with them. By the time they realize I am cutting their nails and they should object, I have already cut a couple nails. I leave the nail clippers on the coffee table, kinda as a decoration, that way I can always just grab and cut.
It is also important to have sharp clippers, so you don't hurt their little feet. Practice makes perfect, just keep trying. Nicker, I don't blame you smacking him when he tried to bite you. When one of my guys mouths at me (which is rare) to get me to stop bothering them I pin them to the ground with my body making sure to hold their head down and away from mine. After a minute I start talking nice and say be good and slowing get off. Be careful though since I don't know your dog, I can't tell you how he would react.
Like I said up top, I have been torturing my dogs since they were small.