Reset your device before update for best experience for next year

[Faraz_F34_5G]

To have smooth experience after update.

Backup your data in any computer or storage.

Completely Reset your phone before update. Then update to new One UI 4.

[ѵօϲɑӀ4ӀօϲɑӀ]

Not before, but after the update.

If possible update using Smart Switch PC.

[BVikram]

Yes, must perform action, for a smooth upgrade without any issues. Especially system admin Apps. As per my personal past experience.