I don't know that this is much better in practice than your solution of just running `sleep` once, but you could run your check with a `while` loop instead of an `if` statement:

<!-- language: bash -->

 #!/bin/sh

 while ! pgrep -f "notification-daemon" > /dev/null; do
 /usr/lib/notification-daemon/notification-daemon &
 sleep 0.1
 done

 notify-send "Take 5"
 aplay /home/Me/Music/brubek-clip.wav

This should guarantee that you don't continue until the daemon is running (e.g. if for some reason it takes longer than your 0.5 second sleep).