I can tell you how I have been doing it for the past several years and it has worked really well for me. I take any of my cows that are 45 days post calving and put a CIDR in them on a Wednesday evening and I give them a shot of GnRh (Cytorellin or Fertagyl). Then the following Wednesday evening I pull the CIDR's and give a shot of Lute. Most of my heats will then fall on a Friday evening or Saturday morning when I am not working and have more time to AI them.
Anything that does not show a heat, I will hit them with another shot of GnRh and let them alone for 2 weeks and then try it again if they haven't show a natural heat in that time frame.
Not sure how everyone else does it but this works pretty well for me.