I sometimes feel like the male characters I play are easier to differentiate from each other, because I'm a girlcreature IRL and they're very clearly A Character Who's Not Me in that way right off, so I'm probably paying more attention to developing personality. For that reason, I feel like I click faster with the ones that work for me, whereas female characters sometimes take me more time. I went through a phase for like three years where I just could NOT make a female character work, for whatever reason. It was kind of bothering me. Now I'm playing a woman who's probably in my Top Three Favorite Children Ever, though, so the dry spell is over. Things come in ebb and flow and such.
On the rare occasions when I alt successfully it's usually when I have both a male character and a female one since, again, I've got that obvious thing I'm forced to be different about and I have it to fall back on to avoid same-y-ness, until the new thing I'm playing has a personality.
Idk if I have a clear 'type.' I tend to play action-oriented characters as my mains, but that's mostly just a vehicle for plot involvement. Personality and backgrounds I try hard to vary. Sometimes to the point where I'm probably annoyingly self-conscious about it, but I like to dabble and see how something feels.