Last night I tried WILD again, and I was trying to keep my breaths from being short or shallow so I was practicing slow and deep abdominal breathing, to be relaxed and stay calm when the panic sets in. but I wondered if maybe it was moving my body too much?
What kind of breathing do you WILDers do?
Actually, I try to mimic how I breath when I’m asleep. That’s the big thing, to lucid dream, you have to fall asleep. 
The trick is, try not to lose consciousness while doing it. So, slow and comfortable breaths.
Deep breathing is good for relaxing. I also sometimes do like Lucid_Mike said. I do it my taking a medium length breath in and then letting the breath out kinda “fall” if that makes sense. Listen to someone breathing while sleeping and you might get what I mean 
xanthier, you could record your sleep breathing with a tape recorder, because I heard it’s a quite individual thing. When you have recorded it, you can mimic it to make your body believe that your mind is already asleep.
On the other hand, I don’t try to concentrate much on breathing, because it focuses you on your physical body. And additionally breathing is special: You can control it, or your body can control it. When trying to WILD I focus on the sound in my ears* because it wont change when I concentrate on it. I can’t take control of this sound by mistake in contrast to breathing.
Good luck 
- Actually this sound I concentrate on seems to be coming from the audio cortex of my brain and not from the blood streaming through my ears.
At some point while slipping into SP, I do hear fuzziness in my ears.