Before a round you want to be loose and confident. This is not the time to practice or work on your swing–this is the time for focusing on one positive swing thought and seeing what your ball flight is like today. My pre-round routine is something like this:
1) Roll some lag putts on the greens and do a drill (gate drill, poker chips, putting mirror)
2) Short game shots including bunkers
3) Half and full swings short->long clubs, taking extra time with wedges and clubs I’ll likely hit on par 3s
3a) I’ll focus a lot on wedge shots from 30-100 yards and hit more shots with short clubs than I will with a 4 iron or 3-wood. I want to put emphasis on clubs I’ll use more on the course. No point in beating 6-irons for half of your range session because you like seeing a tight draw and you can’t seem to stop hitting fades. Play the fade that day. Figure it out later.
4) Smooth swings with the club I’ll use on the first tee
5) A few 8′ putts and a few 3′ putts (no more than 5-8 of each)
My full warm-up session without rushing is ideally about 40-60 minutes depending on how my body feels that day. I never agreed with hitting balls and then doing all of your putting after. I think you want your range session to be as close to your first tee shot as it can be so that rhythm and confidence is fresh in your mind. Combining the confidence of having just hit a great 1st tee shot on the range with having just holed a few 3 footers on the practice green is a great way to start the round.