Whenever I start to read in the Old Testament, I should expect to see Christ there. By 'see Christ' I do not mean that I will always find explicit reference to Christ, or that the OT is shot through with appearances of the preincarnate Word (although there are plenty of both occurrences there). What I mean is that my reading of the OT should be a 2 Corinthians 3:16 experience (read the whole passage to get what I mean). Now, to a very great extent whether in fact I have such an experience is not down to me, but is a work of the Spirit. But it is promised, and therefore the action of faith is to read properly, with expectation, and await the Spirit's work.
So what reading practices do I employ as I set out to read by faith, to 'turn to the Lord' as I read the OT? Here are a few.
1. Look for explicit forward-looking references to the Messiah and his work. Despite all the sceptical work of OT scholars over the last 150 years, these are plentiful. Where you find them, consider whether they might not be the key to the understanding of the particular part of the OT you are reading. It's helpful to consider the particular import of each of these 'previews' of the person and work of Jesus - don't just think 'here's a prophecy of Christ', think through what in particular about Jesus this is highlighting. I personally find it very useful to try to imagine what it would be like to look forward to this as an initial step in understanding.
2. Look for types of Christ. A type is a character who, through their own life and actions, plays out some aspect of the life and work of Jesus. Whenever we look for types, we are engaging in an imaginative process. After all, nobody measures up to Jesus or strictly speaking does anything remotely like what he does. It is more of a case of catching the echoes of the life of Jesus - except these echoes are cast backward through history. Where we do see types of Christ, we should focus first on the particular aspect of Jesus' life and work that we have been reminded of; then (more cautiously) we should ask whether we are being commanded to show that aspect in our lives also (and the type can help us here to think what that might look like).
3. Look for patterns of events which recall Christ's work. Just like the characters who serve us as types of Christ, so events can serve us by bringing to memory different aspects of what Jesus has done. In the OT, we see the work of Christ refracted, as it were, through the history of Israel. Often that refraction will help us to bring out and focus on a particular side to Jesus' ministry which might otherwise get lost in the whole.
4. Look for problems which cannot be solved in OT terms. Where we see a passage which sets up a paradox - especially one of which the author seems very conscious - we will more often than not find that paradox resolved in Christ. These sorts of problems will more often become clear if we read longer passages, or try to fit particular passages into the OT as a whole.
I want to work this out in a particular example - the book of Job - before the end of the week. But I have an intervening post for those who react by saying something like: 'what a terrible hermeneutic! You've already decided what the text will be about before you even read it!'
...Although probably not many of those sorts of people read this blog.