When designing new characters, you want to get the most amount of personality across in your sketches. One way of doing that easily is drawing a day in the life of that character. Where do they wake up? Are they a morning person? Who’s the first person they speak to? Are they late for anything? What do they fill their time with? Who’s giving them a hard time? Who is cheering them up? What do they do at night? How late do they stay up?
Seriously, you’ll learn a ton of information about your character, and you’ll be drawing them in situations that tell a story, rather than static poses. I don’t know if this will help you, but I’ve just started doing this and it helps me massively.