I did it pre RVSM with a F/O and a F/E. RVSM will give you a little more flexibility but even back then there were one way routes so 2000 foot increments. As Galaxy Flyer just pointed out, all bets are off in the real world. Someone gets the flight level you want first, someone ahead is slower than you, etc. We went out with destination fuel plus 10 percent plus alternate plus 30 minutes at 1500 feet.