I’ll be honest; I struggle a bit at Empire, so I will offer an older character.
I used to play a swashbuckler in a cave-based system and I had one prop that made all of the difference, a wine bottle. I would swig from a (plastic) wine bottle filled with Ribena and often topped it up at lunchtime, so my single defining trait was refusing to overthink things. If my first reaction was to run into danger, I would run into danger. If a foe was on the other side of a wall, I would vault the wall with a manic laugh and secretly pray OOC that my companions would follow.
IRL, I overthink everything; that character was me without any real plan or regrets. Refs would ask to sniff my ‘wine’ sometimes just to confirm it was Ribena, I was killed twice (once in an epic one-on-one duel against a dragon, once after losing my right arm and leaping back into combat left-handed), I would go home with some impressive bruises and ache for days, but it was not me at all.
I would love to say all of that came from a wine bottle, but the truth is that the wine bottle was just a reminder of the fact I had accepted his death before I even started playing him. I didn’t want him to die, I was just willing to lose him as long as he died well. Some characters have a life-plan, he had a death plan; he would die heroic, drunk and laughing. In fact, he survived; he is currently possessed by a demon and has got the strange idea that he is now immortal; he even introduced himself to a quest-NPC as ‘king of the undying’ once.
The trick there was simplicity though; a character played in 3-4 hour bursts with a lunch-break to briefly decompress is easy. He fought, he drank, he died, he got back up again. Empire is three days of something more subtle and you don’t just get back up. I suspect that consistency is more important there. Why do you do the things you do and what will that lead to next? Even I struggle with that one.