I have this pronunciation exercise that I do with the vast majority of my “older” students. Most find it extremely helpful, especially when things go like this:
Me: Now we’re going to focus on the pronunciation of “g” and “k” because it’s important to make sure you’re saying them correctly and clearly at the end of words.
Group of teenaged students: ::communal sigh and eye roll::
Later that day playing a game…
Me: Student! Give us a word that starts with “d”.
Me: I’m sorry, what?
Student: ::looks nervously around:: Dik… d-i-g
Me: Oh thank God! DIG! G-G-G-G-G-GAAAH!! You see why my exercise this morning is relevant now, don’t you?