It will take a while and during operation it will say something like this:
Started partitioning on disk3
Creating the partition map
Waiting for the disks to reappear
Formatting disk3s2 as Mac OS Extended (Journaled) with name MacOS Sierra
Initialized /dev/rdisk3s2 as a 7 GB case-insensitive HFS Plus volume with a 8192k journal
Finished partitioning on disk3
/dev/disk3 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *8.0 GB disk3
1: EFI EFI 209.7 MB disk3s1
2: Apple_HFS MacOS Sierra 7.7 GB disk3s2
Now the stick is good to go, transfer the installation image into it:
cd /Applications/Install\ macOS\ Sierra.app/Contents/Resources/
The second thing is, that MD5 signed root certificates aren't accepted anymore as default. Unless you're doing some weird shit like I, you won't notice this change. This is fully documented and know before. In optimal world we wouldn't have any MD5 signed root certificates anymore.
Other than those two, I continued using my macs as usual.