I don't know where I first I heard this, but I've had such success with it in both my teaching and my tutoring that I wanted to share it. When students are converting from logarithmic to exponential form (or vice versa) there are two words that have become my new best friends.
Basement and base.
For the most part, students seem to know exactly where to go when switching from one form to the other as long as they start out right. How do I ensure I start out right? I just remember: "What's in the basement becomes the base." (Or vice versa)
Does this solve all my problems? No. Does it guarantee that students fully understand what a log function is? Absolutely not. But, I want my students to be able to covert from log form to exponential form like it's nothing. And this helps that process some.
Maybe this is widely known already. But I still heart it.