I have a really back-and-forth process -- I start with small pencil scribbles of a page, adjust them digitally, print those out and do roughs on paper, scan them in, touch them up digitally, do perspective grids digitially, then print that out and do my pencils using pencil and paper, scan & print, then do my inks using pen and paper, then scan and colour digitally in photoshop!
It sounds really overcomplicated whenever I write it all out, but I sorta developed this process really slowly by trying different things and going with what made me able to work the most comfortably!
I draw the character tons of times, from different angles and with different expressions. I kinda pay attention to what makes the character look like themselves -- when I draw them and they look "off," I try to figure out what I changed. After you've drawn a character over and over and over and over again, it's a lot easier to keep them consistent.
If I haven't drawn a character in a while and they're not coming out right, sometimes I'll take a break to do a couple quick sketches of them outside the comic, to get the hang of them again.