I've recently rebuilded my carbs and also attached the cables after I mounted the carbs.
And I'll have to agree to the above; it's probably easier to attach the cables prior to mounting the carbs.
But anyway; in my case it wasn't to difficult.
Maybe I was having some 'beginner luck' but they pretty much snapped in place with the first attempt.
The things I used were a long nose plier, a fine pulling hook and an extra set of hands.
I don't remember exactly how I did it but I know I removed the cables (or loosened them there, don't remember) from the mounting bracket which is attached to the float bowl.
My daughter pulled the cable towards the exact position and with the long nose pliers I popped it in place.
One remark here (as bigbadass2 allready mentioned) : if you follow this procedure; make sure you adjust the freeplay to the exact point (at the mounting bracket). Too tight and you'll end up with a throttle cable which doesn't snap back, too loose and you'll end up with too much free play in your throttle.
1997 Ducati 900 SS Full Fairing