The old interview advice still stands. Be yourself. Simple as that. Look into what you're signing up for as well, interviewing officer needs to know that you understand the committment required etc.
Aptitudes.... little you can do, however do not drink alcohol in previous 4-5 days, make sure you are well slept etc. It's probably the hardest you'll ever focus on something for 4 hours.
Good luck with it, the FAA are desperate for fast jet pilots(but overwhelmed with heli pilots).