Good endurance base, throw in some climbs, short sharp, long slow, ride in and out of the saddle, mix it up.
Suffer well and enjoy.
Oh and remember to take in the views and not just the tarmac 2 meters in front of the bike :-))
Depending on your fitness level if the alpine climb is 20+ kms long then I work on a 2 hours climbing or there about.
Never done a time trial, but the word "simply " is not one that springs to mind when describing any of the riding I have done in the Alps.