I can pack for a 1-2 week trip in under 30 minutes, a shorter trip in maybe 10 minutes. Here are a few techniques that have helped me reduce the time required:
1) I keep a set of toiletries plus toothbrush and hair brush dedicated to travel. This saves me the time of rounding up my regular items from the bathroom. It also greatly reduces the chance that I forget some toiletry.
2) I keep these toiletries and other items I customarily use only for travel (e.g., a light canvas satchel and my secondary pair of swim trunks) on a shelf near my laundry, where I pack my bag. Having many of the items I need near to hand helps cut the time. It reduces unpacking time, too, as I only have to put these items back on their dedicated shelf.
3) Finally, practice makes perfect. Traveling numerous times per year helps me get the time down.