I've got large fingers and two clips with the nail clippers leaves a jagged edge and sharp corners, I don't use an emery board though, I just use that little metal file thingy that's attached to the clippers, one or two swipes and I'm all good. The problem is that the hard corners dig into my skin, I'm like really old or something so my nails have gotten harder as I've gotten older, in my youth I'd just bite the edges off, I think if I tried that now I'd chip a tooth on these damn talons!
On my toes, I've been doing this thing for over 30 years now, I cut them straight across with a pair of little grooming scissors. Twice, in college, I got ingrown toe nails from ripping the nails off and I had to go to a med check to get the infection taken care of, this happened like a year apart. Fortunately or unfortunately (however you look at it) I got the same Indian doctor both times. The 2nd time was pretty funny, the doctor sees me, his eyes grow huge and he says "You again? What is your problem man? I TOLD you the last time to cut them straight across, clearly you have NOT done what I told you to do, stop wasting my time, I will fix it this time but you do not need to be here, you need to listen to me and cut the nails properly as I have told you."
The ingrown toe nail thing sucks because I had to get the toe numb with two shots, this was the big toe (both times) they cut the nail down to almost nothing and when the numbing wears off it is pure pain for several weeks, anything that touches that toe it's pure torture, needless to say, I learned my lesson that 2nd time and I haven't had an ingrown toenail since, wearing the correct shoe size helps too, I was wearing a half size too small I think at the time.