One a time is plenty. Although more than one at a time can be fun from time to time, typically one is enough. (I am terrible at multi-tasking)

Ghost summed it up well. They feel great when allowed to be free and can be uncomfortable at best when restrained. "Morning wood" isn't always sexual and can feel different (hard but not pleasurable) than when sexually aroused. An erection coupled with arousal has a great deal of heat, whereas a "piss hard on" doesn't. I think it all comes down to state of mind and/or how long it has been since the last orgasm. I do know that the longer time between cummng, to more frequent and intense the erections become. Sometimes they go away on their own, sometimes not. There's a grain of truth to the phrase "thinking with the little head". I swear, he has a mind of his own.

big ones, medium ones, or small. We really just wanna see them. Freakishly big, fake boobs are a turn off.

I masturbate as often as possible, usually depending on my workload. Typically it is 4-5 times a week. My favorite way has lately been in online chat rooms on cam with multiple women watching (doesn't bother me if guys watch).