Three Club Flash
Using double or triple spins, throw all three clubs quickly into the air one after the other, so that they cross to the opposite sides, as in a cascade. If you were quick enough, then your hands will both be empty for a second before the clubs return. Clapping your hands together while all the clubs are in the air, is a good way to practice this trick, and it also shows the audience what has happened.
A common cause of difficulty with this trick is that one or more of the spins are wrong. In my experience people often under-spin the last throw a little, but you have to watch yourself as you do the trick - everyone makes different mistakes. Don't just switch off as soon as the clubs hit the floor, instead think - which throw/s did I miss? what was wrong with them? Concentrate on the throws that are giving you problems.
Experiment with different heights and spins, a nice combination might be to juggle with low, fast doubles, and then do the flash with slow singles or floaters. Although most people use a cascade pattern for the flash, there are those who prefer to throw all the clubs up in columns instead, try both ways and see which suits you best.