Since we find ourselves fashioned into all these excellently formed and marvelously functioning parts in Christ's body, let's just go ahead and be what we were made to be. Romans 12:5 (Msg)
The best way to discover your spiritual gifts and abilities is to experiment with different areas of service.
For instance, when I was younger, I could have taken a hundred tests to determine my gifts and abilities; yet, they would have never told me was gifted at teaching. It was only after I began accepting opportunities to speak that I saw the results, received confirmation from others, and realized, "God has gifted me to do this!"
Many people get the discovery process backwards. They think, "Once I discover my spiritual gifts, then I'll know my ministry." It actually works the exact opposite way. Until you're actually involved in serving, you're not going to know what you're good at. The thing to do is just start serving and experimenting with different ministries; only then will you discover your gifts.
You have dozens of hidden abilities and gifts you don't know about because you've never tried them out. So I encourage you to try doing some things you've never done before. No matter how old you are, I urge you to never stop experimenting.
Over the years, I have met many people who discovered hidden talents when they were in their seventies and eighties. In fact, I know a woman in her nineties who runs and wins 10K races; she didn't discover that she enjoyed running until she was seventy-eight!
Don't try to figure out your gifts before volunteering to serve somewhere. Just start serving. Try teaching or leading or organizing or playing an instrument or working with teenagers. You will never know what you're good at until you try. When it doesn't work out, call it an "experiment," not a failure, because it will help you eventually learn what you're good at.