I spent Saturday morning at the slalom gates at the Cedar River alongside Landsburg Park near Ravensdale (thanks to slalom kayaker Joey Yeaple who organized an all-welcome event to get people working on technical skills.
I absolutely love working on slalom moves, not that I'm proficient at all, I just notice that practicing being precise and consistent on even very easy water transfers directly to a noticeable benefit in significantly harder whitewater - it's amazing.
And just for the record, you don't need to be in a slalom boat, I was in a Dagger RPM and it's totally fine to bring a creekboat or whatever you may have.
If you'd like to join in on slalom practice, check the League of Northwest Whitewater Racers page to see if they're holding any. You can also show up to slalom races like the ones they hold at Salmon La Sac and the Nooksack - even if you're just a pleb, like I am. :)