Do what they do with the players...Full time during the season, and during the off season, most have other jobs.
PAY THEM WELL!!!
Also, invite twice as many officials as needed to a training camp, and cut the ones that don't measure up. They can always come back again next year. If you want try-out games, they can be CIS, Preseason CFL, or even Junior ball.
Just like the players, returning veterans usually begin as starters and the job is theirs to lose. A stellar rookie can step up and take the position with great execution.
(In the case of officials, really poor execution could wind up in...well...execution :lol: )
During the season, they study film of the teams they will be seeing next week, and prepare for them. They can run daily drills on field for fitness and mechanics and position.
Officials could be sent to the "bus squad" of the CIS or Junior during the year if they have a brutal outing, and "minor league" officials could be brought up to replace them. (Just ask Louis Sakota of the Riders how that works)
Its a pro league. Treat the refs like pros. Instill some pride in them. If they are made to feel like amateurs, they will surely perform that way, as we have seen.