Well, all I can tell you about using a manual gearbox is just general stuff like "Looking at the gear lever while shifting is a bad idea..." that doesn't help you 'cause you already know that kinda hints. I hope...
I guess the secret of a manual is to shift without thinking about what you're doing. Like the others already said: practice is the key to become a "driving god". And that doesn't take minutes, it takes months until everything happens automatically, without thinking of the clutch's sweet spot or which gear to choose...
And when you're got used to your car, you still have to adapt, when you have to drive another car. Because different cars, different behaviour of the clutches: when I started driving I had an old Golf Mark 2 that was tortured for nine years by an old lady who used the clutch pedal as a rest for her left foot. The result was a weak clutch with a sweet spot near the upper position. I just had to look at the clutch pedal and the clutch slipped instantly. But I got used to it and thought I was a good manual shifter until I had to drive a friends car with a brand new razor sharp clutch. Damn I stalled that bitch a hundred times, a police car next to me also made me nervous, that was a bad day for my ego.
I have driven many different cars during the last ten years, so I need to adapt for a new car only a couple of minutes.
It might also help if you have the opportunity to practice with a different manual car (not as nasty as an Impreza), preferably with an experienced manual driver as a passenger like avanti said. The more cars you have driven, the easier it gets to get used with a manual.
By the way: Did you ever had driving lessons in a manual car or is it uncommon in Canada?