Completely disassemble it, and somehow creatively coordinate the pieces with other parts of luggage? For example, you could turn parts of the casing into extraneous hinge pieces for the suitcase, integrate parts into the interior of an electric shaver...
Make it out of something that is less easily detected.
And then hire a hot woman with a lot of cleavage and a short skirt to go through security at the same time as I do.
You can tuck a "CIA letter opener" in your sock. It's a "knife" made of fiberglass reinforced nylon, totally undetectable as it contains zero metal. It is very tough and will hold a decent edge. There are few variations out there like the "delta dart", same concept but a triangular blade (more like a spike). I have both and they're great weapons.....for Spycraft, of course.
The same goes for pistols. A company recently (within the past 8 years) made 9mm out of ballistic plastic where the only metal was in the firing pin... I've heard talk of ceramic 9mms as well but haven't seen them.
The good about the plastic gun: All you need to do is smuggle in in peices amongst other inocouis junk, then assemble it and buy ammo... The bad it wears out faster as the plastic doesn't hold up to the explosive gases and the heat as well as metal (okay they have a live expetancy of around a year and half with daily firing... but you could easily reduce that and start giving penalties to the ranged shots...)
The ceramic gun: Agian this is only speculative as I haven't seen one (and really stopped being into guns about 6 years ago). It should last almost as long as a regular gun. The bad: Easier to detect using x-rays...
with a knife, I would get a porcelain one- used mainly or cutting cakes and such- but hey- anything sharp and pointy would work for a knife- even a letter opener, or nail clipper... or you name it
as for gun... just unplug the metal detector before yuo pass by. Its funny because after teh 911 incident, these things plagued LAX- and the funny thing is- nobody noticed that the red light was flashing (flashes when unplugged)
and yes- hiring a hot blonde will work too...but then again most customs agents are big ogrish females...but then again again- they might swing that way.