I would say that an internship with a corporate flight department would be the #1 way to get a foot in the door. They may not hire you right out of school, but they will certainly keep your resume at the top or the stack for when you have their minimums (assuming you did well as an intern). It also looks good to other corporate operators if you have some internship experience with a recognizable flight department in your past.

Otherwise, and to build time, a good progression is flight instructing, then pax charter, then maybe a Fractional operator, then start knocking on flight dept. doors. I say pax charter and Fractional because they put you in the same circles as corporate operators for networking purposes and season you for the job of flying people around. You may also get to add a type rating or two in the process and this never hurts when looking for corporate jobs. The job of flying corporate is quite a bit different than freight and different than even regional airline flying.

In corporate flying, like it or not, the passengers are King and the sooner you realize how to keep them happy, yet still be able to educate them to the fact that you are the boss when it comes to safety and dealing with ATC constraints, the better you will succeed. It's a fine balance sometimes and not everyone is good at it, even if you are a top notch pilot.

It's hard to argue with the fact that the regionals are hiring like crazy right now and it's a good way to get some fast time in the logbook at the moment, so that shouldn't be overlooked. The only problem is, it can be hard to convince a corporate operator that you aren't planning on returning to the airlines at the first opportunity of a primo Major job. This is known as having the "airline stink" on you. You may wind up liking the airline side of things, though.