Bob Fisher had an ingenious count
...Called the modulo 10. This follows baccarat-type scoring where all cards count face value and you subtract 10 from any number greater than 9, eg 6+7=3, 5+9=4. It is relatively simple to use accurately if you are dealing through a pack one at a time, allowing you to accurately predict the last card. I used it for a TV promo on card counting once.
It would be relatively simple to develop a similar system to incorporate suits, though ultimately, what you have is a relatively unimpressive magic trick. We are not magicians, what we do is real but unspectacular showmanship.