Como dizer "Faltou fazer..." em inglês

Yes, Jessica, I agreed.

Outra:

I have yet to tattoo the (wedding) ring.

Mais uma:

"I still have to tattoo the ring (on-obviously-his ring finger)"

It's not a professional context, I'm talking about a personal experience, in which my boyfriend and I planned a lot of things, but one we couldn't do, and it was the "tatto ring". We did everything, except the ring. I thank you both, but I think the suggestion from Telma is more appropriate.
Thank you so much!

Ah, my suggestions were like you was saying/pointing out that to someone else.
If it´s you saying about your own job/plan/task etc, these ones would do:
It´s lacking the ring.
What I need to do next is the ring.

You wouldn´t say that "you forgot" in such case, it would work against you (and the perceived professionalism of yours.)

It´s lacking the ring.
You forgot the ring.
It seems like you forgot the ring.

The last one softens the statement, it´s good not to seem rude.
On the other hand, Lois P. Frankel (author of the book Nice Girls Still Don´t get the Corner Office) would say that it weakens it. By this reasoning, it would seem like you are making a tentatively affirmation, not much confident. So, it goes with the setting and the message one tries to convey, and the audience as well.