Your question is highly open to interpretation based on the situation/problem to be solved.

Personally I would still avoid using our variables, but in some situations I wouldn't hesitate to use a handful of my variables directly underneath use strict; use warnings;

Also, if these global variables are constant for the duration of the script's running lifetime, then you might consider using use constant or use Readonly::XS

Or, if you have complete control over this code, restricted hashes might be a suitable fit. Essentially you would declare a hash in your most outer scope, then using the Hash::Util module's lock_hash() and unlock_hash() subroutines whenever you need to modify or "make constant" your global variables...

Disclaimer: This is just my opinion, and others may disagree with these approaches.