Interesting question as Morse code is quite efficient for communications.

Children today don't have access to such devices such as the Mego Star Trek communications console anymore.

https://www.youtube.com/watch?v=bUesQ6wA4Uo

I don't think that they teach Morse Code at High School today, but alas youngsters can be surprisingly adept with predictive word texting, where I'm at a complete loss when using this text mode.

https://www.youtube.com/watch?v=6hcoT6yxFoU

The Smitty Harris tap code would probably be the best way as it is simple to remember and easy enough for others follow and understand, but in the UK it would have to be adapted as folks in the UK are more used to Column first then row next implementation.