i've seen so many dumb ppl with the manual, leaving 1st gear in for downhill...
best would be 1st gear in for almost every parking except downhill you wanna do reverse
During the winter especially when I leave my car outside the lot or even in my own garage for 3+ days, I don't use hand brake but use just 1st gear in, during this cold weather and long term parking hand brake isn't the ideal way as it will bite the brake for a long time.
keep in mind this is a flat level/surface parking, not downhill or uphill
the whole beauty of manual is that you can simply put in gear when parking, and is a way better way than using hand brake.