"What is the hardest thing about character creation for you?"
I always struggle with protagonists. I have a tendency to make a protagonist, then to make a bunch of side characters who are inevitably more compelling. I actually combat this by making a dummy main character, building my cast, then swapping in whoever works best thematically from the "supporting cast" for the empty dummy.
My other nemesis... male characters... I just always feel like there's so much more room to make a really unique female character I haven't seen before, wheras dudes are so ubiquitous in the genres I work in I always feel like they're a bit boring and like "yeah we've seen this guy..." so I tend to end up making a cast full of really colourful women then go "ugh I guess some of these should be men..."
"What is the easiest thing about character creation for you?"
I can come up with a character's voice on the spot. It's really handy for DMing or GMing tabletop games. Their voice, speech pattern, vocabulary, colloquialisms and even things like posture and gestures are very vivid in my mind, so "character voice" is really intuitive for me.
"How do you choose names when creating characters?"
Errant is a bit of an outlier because the characters date way back to older work from when I was about eighteen and my approach was "just throw in some syllables and whatever sounds cool." Nowadays my approach is: "Think about who gave them this name" So we all have, or have had in the past, a name our parents gave us, and that name always reflects our parents in some way; what they wanted to say about themselves, how they felt about this little crying blob they'd produced and what they wanted you to be. In many people's cases, as they grew up, people (maybe with some kind of guidance from you) may have settled on some kind of nickname for you, or maybe you picked a new one yourself. I always try to have some kind of logic in mind of "who gave this person this name, do they like it? Do they suit it? Do other people like it?"
If you were named Robert, you could be a Rob, Robbie, Bob, Bert, Bertie or maybe you ended up with a more wacky nickname like Robo or Robsie, or a nickname that has nothing to do with your name like "Lucky". Or you might have entirely divorced yourself from Robert and chosen a name for yourself, and that's always interesting because then it becomes "who do I want to be?" and "What do I think suits me?"
I always find it weird when a character has like... the most ridiculously badass name and it's just one their parents apparently gave them and I'm trying to imagine the scenario where their parents who ran like... a grocer's shop in a little village named their kid BLAZE WOLFHEART. Like, I'm sorry, were your parents actually huge nerds or did you really give yourself that name and they originally named you Robert?
Surnames are generally easier because it's all about just thinking about the character's lineage and choosing a name from an appropriate area that goes together nicely with their first name. If it has an appropriate meaning, that's a nice bonus.
One sentence of advice for a newbie character creator:
The lies your character believes about themselves are some of the most important things to nail down when creating a compelling character.