Roleplay Character Development Help? (Backstories mostly)

[Frostfall]

Hello! I was wondering, how do you guys develop your characters' backstory? I know at least a basic backstory is going to help me roleplay my character and stay consistent, but how do I make a good one? I've tried to look at guides for making characters, but they are all for essentially design solely while I am looking for the actual roleplay bit in creating a character. But if there is a good guide about this somewhere, please show me, I would love to read it, or if you have advice to give me here I really want to hear it. Please and thank you, I'm just stuck when it comes to making a backstory that will let me really have developed characters, even if not that complicated or 'special' of a backstory.

[Knowbee]

Usually when creating a character backstory, I focus on what they fail at and what they look like, mentally and physically. I always keep in mind what I want this character to be perceived as, "Tough" or "Brave," and I go by that and tell about why? Who did it? How did it come down to this person acting this way to others? When thinking about these unasked questions it could be from family, friends, enemies, or an unknown source that wouldn't quite 'act/treat' the character(s) rightly or a bit suspiciously. [Sowwy of I couldn't help >w< I tried] <333

[Telluric]

music.
lots of music.

listen to lots and lots of music. vary the styles, listen to artists from 30 years ago or a song just released yesterday. the tunes will give you a great basis if you can relate them to the character you're trying to create.