Breaststroke Pull Technique

I could use some advice from experienced breaststrokers on the proper pull technique. I have a naturally good breaststroke kick, which probably makes up 90% of my propulsion at this point. I know that breaststroke is the stroke with the most potential for me, but I seem unable to get the right feel for the pull. Every once in a while I have one of those really smooth swims where I can feel myself riding the wave, but I cannot recreate that at will. I've tried the hand paddles drill where I swim BR with the paddles on backwards so they are not attached to my hands at all. I can keep the paddles on pretty easily. I think I'm using the right basic technique, at least based on all the descriptions I've been able to find. Yet when I swim ***, my coach says that my arms look "stiff", like I'm not turning them in enough. I would like to understand what the proper pull should look like and feel like, before I start increasing my yardage and intensity. TIA