I am a novice but I would focus on Starwood to the extent you can for the simple reasons that the points are most valuable and the redemption prices are good and the rules/availability fair. Plus, their properties are nicer albeit more expensive in many cities it seems. The only drawback is they have fewer properties.
To the extent you can't find a starwood, stay at Hilton and take advantage of your status for the simple reason that status is not worth anything unless you use it.
[This message has been edited by LemonThrower (edited 05-14-2002).]