In a normal sentence, you don't include "did" before the verb:

She told some interesting anecdotes.

But when your sentence is contrasting with something else that you just said, you should use the word "did" and place a strong stress on that word when saying it:

I didn't think he was that good-looking. I did like his hair, though.

In the example above, you're contrasting this positive statement about the speaker with your earlier negative statements.