river swimming against the current

I am a longtime pool swimmer but relatively new to open water. In the last year, I've had a handful of good workout swims in the Gulf of Mexico (while on vacation) and in a lake (here at home), so I've gotten a chance to get a feel for things like sighting, navigating, and adapting my pull to choppy waters and surf--enough to have a decent understanding of what I need to work on, anyway, and enough to know I want to do more OW swimming. I've also always been a bilateral breather, so that's nothing new. What I haven't been able to do to this point is river swimming, but I have signed up for a 1.2 mile river race in a few months. The first leg will be against the current. Is there anything I should be keeping in mind/training for that will help attack that current head-on? I know that kicking is often not as prominent in an OW technique, but I am a strong kicker, should I be playing around with the intensity of kicks, so I'm ready to ramp it up when I'm pushing against the current? Once upon a time I swam fly and IM in meets and still do a fair amount of fly in my workouts--would a dolphin kick serve any advantage against the current? Or is that a ridiculous notion that would wear me out too much too early? Or is the main thing adjusting my pull to be fast and strong?