Well, shooting outside of cons is much easier, since you have a nicer environment, a lot more time on your hands to think about what you're doing, less distractions, and a lot less to worry about.
Poses and angles should come naturally when thinking about the character and what you want to tell about him. If something doesn't work, take time to adjust it : experimenting is the best way to learn. Think about photos you'd like to see, and just try to make them.
My general tips would be : don't be afraid to try several settings, several angles for the same pose. You're on digital, so take as many photos as you need to get the one you imagined. Also, post-process - good post-processing can really bring out a mood for a shoot. And be very selective of what you publish (my average for a 2 or 3-hours shoot is between 20 and 30 shots published).