You ran out of tags while conducting a lockout/tagout and it’s a long walk back to the shop to get more. But you do have a notebook and some tape. Those tags are just paper anyhow, so why not save time by taping up a sign?
Handwritten signs are not OK. Those lockout tags are readily identifiable; people see them and know what they’re for. They also know not to remove tags or disregard them. The same applies to locks and hasps.
Each lock of yours is uniquely identified as your lock (perhaps engraved with initials or a serial number). So don’t use just any lock or borrow someone else’s lock.
What if there aren’t enough tags available? Executing poor safety practices on top of poor planning doesn’t balance things back out. Someone must get more tags so that each isolated energy source can be properly tagged.
What if the lockout requires more locks than you have? In larger facilities, it’s easy enough to get additional locks issued. In smaller facilities, a trip to the hardware store might be necessary. Make sure any new locks are specifically identified as yours.