The past tense is your "go-to" when talking about things that you remember about someone... the present tense is still useful, however.
Since you can confidently use a colorful idiom like "a face for radio", I think you're probably advanced enough to really play with the language. With a little imagination, you can toy around with the past tense and present tense to draw the listener in.
For example, what you recall could be expressed thus:
"I remember [present tense] one of my teachers in middle school. Although he has [present tense] a face for radio, he has always had [past perfect progressive tense] a unique talent for saying things in a way that made [past tense] him popular with his students."
Technically, you might be breaking or straining a few dozen rules of the English language, but... well, there are no rules of the English language that the English language itself doesn't break on a regular basis. Remember, you're telling a story, so you can use poetic license... it's one of the perks of the language.