laser is the best--with a long throw will provide the extreme amplification of the vibration needed to see when the low frequency swaying is at a minimum. You can point the laser in any direction--behind the camera even, so it doesn't show up in the picture. note there will be more than one axis of vibration and the torsional back and forth twisting (left and right) is probably the biggest problem as the general tripod construction with long thin flexy legs and a big camera with big rotational inertia on top provides a natural torsional vibration system--back and forth ("left and right") rotation about the tripod column axis. the bigger and heavier the camera, the more rotational inertia and the worse the problem--the longer the tripod legs, the more spring action and the worse the problem. A thin twisty center column will make the problem worse too--keep that column from extending.
Also, for big cameras with long extensions, you have that "up and down" vibration--when the camera is racked out the rotational inertia is increased and it bops up and down about the tripod mount--this is more the flexure of the camera itself about the tripod mount and if the column is extended up--it can be minimized by a bigger tripod plate--connection surface between the camera and the tripod and not extending the center column.
as soon as the swaying subsides--a breeze comes along and starts it all over again. The physics of the system shows that this is generally not a problem with small , lighter cameras (as long as they are on reasonably rigid tripods)--only big heavy cameras with big mass that can store keep vibrations going for a long long time.
high frequency vibrations tend to die off very quickly unless they are being driven by some outside force and are near the resonant frequency of the camera/tripod system.
You can carry an empty canvas sack and some paracord...
