A couple of things: Try not to obviously look at your feet to see where you're going or to negotiate steps, etc. Try to look through the center of the T visor instead.I was wondering if there's any Boba Fett specific pointers.. LOL?
Practice holding your blaster in the ways Boba did in the film. I think there's basically 3 different poses.
Posture is important. Don't slouch if you tend to like me. Try to keep your back straight and your feet spread when standing still. When walking, make it very much like a march.
At the last con I tried to limit my chit-chat. People would ask if they could take my picture, and I'd make an uncomfortable pause before saying simply yes. Or better yet "as you wish". But the pause was intimidating. I didn't do that with kids though, also lots of fist bumps with kids, I made a special effort to also do this with girls.
We also did a parade through the con and I tried to watch people as we went by, sort of scanning the crowd as we walked, especially on the exposed escalators. I recall one young lady pointing at me excitedly to her friend so I quickly transitioned from holding my blaster across my chest to pointing it at her, she jumped, and laughed, it was fun.
If there are other star wars costumers there try to hang out with them but behind and off to the side, especially if there's a Vader.
Hope this helps.