I was taught to pish in a course for beginning birders. (At least one prominent North American birder prefers 'spish' because of an alternate meaning of pish--another activity often performed in bushes.)
I've demonstrated pishing (the birding meaning) to non-North American birders visiting the States, and on trips in South Africa. I get amused at the initial reactions of the birders, then their delight when birds start showing.
I don't use the kissing the hand routine. It interferes with binocular use. Instead, I just make a variety of mouth/lip sounds, usually in a lisping, whispering mode. The different sounds are used to attract different species and to keep them around a bit longer.
One sound is similar to the 'pssst' people use to attract the attention of another person. It is done in a sequence of 2, 3 or 4 repetitions, a pause, then more repetitions.
Another sound is "pea soup, pea soup, pea soup" in a harsh whisper.
Other variations are often effective. Find what works for you.
These sounds usually bring in chickadees and titmice, wrens, kinglets, nuthatches, cardinals, jays, small woodpeckers, and sometimes wood warblers. Other species may follow to learn what all the ruckus is about.
An additional use of the technique is in conjunction with owl calls. Here, in the midwestern U.S., an imitation of an Eastern Screech-owl (not a tape recording, but a human-generated sound) often attracts a small crowd of inquisitive, scolding birds. The owl sounds are alternated with pishing. The pishing is the imitation of scolding birds. The birds are attracted to the vicinity to join the 'mobbing' activity.
Even as I endorse pishing and imitating small owls, I urge that the technique be used sparingly, and not mindlessly as I have sometimes experienced when birders are exasperated with slow activity.
One last comment. A football coach at the University of Missouri known for his "ground game offense" once quipped that three things could result from a forward pass, and that two of them were bad. The same holds for pishing/owl imitation. The birds may be frightened away; they may suddenly become quiet, although they were vocalizing before; or, they may come close to investigate. That's when it is fun!