Experienced kendoka are expected to have a “Tokui waza” It translates as “Unique Technique” , although it is generally thought of as favourite technique. Think of Eiga san’s tsuki and you have the kendo definition of tokui waza. Most strong shiai players have a technique that continually wins their matches; but of course, it is not their only technique. It is the one at which they excel and that which beats their opponent no matter how much it is expected.
Tokui waza as a concept, probably came from Judo, where your favourite technique was dictated by your physique. A tall long legged person might excel at uchimata and a short stocky player might prefer seotoshi. There is an element of this in kendo – tall guys favour men, shorter people kote, but there are no rules.
I am not sure if I really have a tokui waza. There are two possible candidates at the moment suriage men and kaeshi dou. Both have been equally effective in keiko and shiai, but they work best in different situations against different types of opponent. My own tokui waza have changed over time from hiki men to degote to debana men to the current favourites.
How do you develop tokui waza? You need to try as many techniques as possible and find the one that suits you. But there are two serious caveats. Do not try overly complicated waza until your basic ki-ken-tai-ichi and cutting technique is correctly established and do not continually over use any technique with the same people in jigeiko. For example a katsugi men or gyaku dou, every blue moon, may startle the strongest opponent, but try it several times in the same keiko and watch the bored expression on your opponents face.
So the answer in my view is to practice new techniques as drills – a few at a time and keep going unti you can do them well. When you feel something really works, try it now and then in keiko against different types of opponent. Another caveat; be careful about using techniques like tsuki on venerable hanshi unless you know them well. When you are comfortable that your tokui waza works and you can make it happen at will, then it’s time to use it to win shiai.