@PC99:
I'm assuming he/she knows how to solve a 3x3 normally right? Or are you teaching him/her how to solve a 3x3 normally with a BLD method? If that's the case, I wouldn't recommend it since it's more confusing and boring compared to a more intuitive approach like LBL, so it's easier to lose interest and not move to BLD at all.
If he/she does know how to solve it already though and you're just teaching BLD, that approach is fine. The three steps I'd recommend for teaching BLD would be: Practicing with eyes open and looking at the cube; Writing down the letters/numbers/whatever you plan on using for memorization and solve without looking at the cube (just following what you wrote); Fully solving BLD.