If you have a tach with replay feature - it's pretty easy to see the clutch engagement.
With the analog graph display it's even easier still.
With the driver in the seat, the engine (and clutch) warm at an idle; from a standing start, go wide open throttle and accelerate while holding the steering wheel straight (ie drive in a straight line..)
Watch the engine rpm climb on the tach (3400, 3600, 3800, 4000, 4200, 4400, 4000, 4200, 4400, etc.) The rpm will climb/drop several times in very small increments (obviously not 200 rpm per my typed example.) The very first time that the rpm drops is your clutch engage. Now, the rpm may climb and drop several more times after that initial drop -- this is typical of clutch chatter. Some chatter is acceptable, too much means that the clutch is probably ready for a rebuild (close the air gap, etc.)