Here is my advice
1) Get in the upgrade queue right after making your reservation. Call reservations for this
2) Check in 24hrs in advance if the upgrade doesn't clear by then. ALSO, at the airpost ask to be put on the upgrade list.
3) Learn how to read fare buckets and use booking tools like ITN
4) Use #3 to determine which flights to take.
5) read, read, read and search for posts here on FT. It is a gold mine of info.
6) enjoy each upgrade