I've been using the Fiona Clearwater files available on youtube lately and I've run into a bit of a problem. She can get me deep enough that my conscious mind switches off, which is a milestone for me, but then I start to dream and lose focus on her words. The randomness of whatever is going on in my subconscious will suddenly respond to something she has said after I've accidentally tuned her out and I'll realize what's happened, then my conscious mind switches back on so I can try to focus on her words, but it feels like I come up out of the suggestible zone and nothing sticks.

Is there something in particular I can do to make this work right? Or do I just need more practice?

I can't remember the exact names, but I think there's some good info in two threads. I think they are called "tranceless indeed" and "scratching the itch". Some interesting advice in there I recall!

As for "practicing", I always recommend trying out meditation.