How to Get to Christ From the Old Testament

The key verse is almost always Luke 24 verse 27. It's in the passage about Cleopus and his companion meeting Jesus on the road to a mess, not recognising him at first. We hear a lot more about finding Christ in the Old Testament or preaching Christ from the Old Testament. But after confessing that sometimes today I'm left with the feeling that it's being done in a very mechanical way. There are actually books that will tell you the five or the seven or the ten ways to do it.