I dunno if you'd call it a 'trick'... but you can use applescript to do lots of things...
just open your applescript editor and type this in:
tell application "finder"
say "hello"
end tell
there's your first custom use of the speech recognition lol... there is lots of info on the net if you google applescript and speech recognition that will get into more complicated uses.
https://forums.macrumors.com/threads/523296/
Go there, and try out the application i posted. Bugs aren't all out, but you'll get a taste of what you can do. Remember to copy/paste the code into applescript editor, save it as an application file to your desktop THEN run it. Also, make sure your speakable items are on, calibrated, and don't require a keypressed or keyword (all changable in system preferences - speech)
Once program is started you can say:
"Towers Timer" - Starts a five second timer.
"Thank You" - To thank the timer for reminding you about the time.
"Quit Timer" - to exit the program.
I wish i could explain more in detail but im dead tired. Got a tooth pulled, and im on vicaden ^^
