We have lovingly dubbed our table "pink tie" because we try to go in black tie but end up improvising in the worst way half way through.
Oh we need to sneak in? Uhhhh ok here is what we do. Hack the employee database, find Tim the IT guy. On his way home kidnap him, stop at a fast food place and demand to know his order, spend 2 hours roleplaying his interrogation. Ultimately decide to pretend to be a pizza delivery person dropping off pizza for a meeting, then say you need to use the bathroom to get an excuse to wander around. Get to the server but panic as you realize it's been too long for the pizza guy to be "in the bathroom". Rip the server off the wall and chuck it out the window and have the mage catch it with magic. Get caught trying to sneak out and get into a fight then hide the body in the janitors closet. Security on the way out gets suspicious about the blood on you. Explain it's marinara sauce from dropping the pizza and start crying on demand about how your boss is gonna fire you because you suck so bad at your job and how you CANT miss rent again or you'll be evicted and and and-. Roll deception VERY well. Make the guard uncomfortable so they shoo you out.
Success!