Network, network, network.
If you have a side-hustle, it never hurts to have it in the service industry.
Don't let anyone (student or instructor) at your flight school graduate, move onto greener pastures, etc without trading contact info. Buy 'em dinner for their accomplishment
If you really wanna go pure 91/corporate....go 135/121 first. Get the flight time that you'll need to land that unicorn. You'll never build the time you need if flying for one of the dumpster fires referenced up-thread.
With 135, there are plenty with rotational schedules (17/13, 16/14, 15/13, 12/10, 8/6, 7/7), so you can experience whether that fits your lifestyle.
With 121, you can experience whether you like the 2-5 day schedule instead.