It's fairly minor, but using concatenation when you could use interpolation instead tends to obscure the result you are aiming for. Compare the following two print statements:

use strict;
use warnings;

my $tsuJ = 'tsuJ';
my $rehtonA = 'rehtonA';
my $lreP = 'lreP';
my $rekcaH = "\nrekcaH";

print join ' ', map {scalar reverse} split / /, $tsuJ . ' ' . $rehtonA
+ . ' ' . $lreP . ' ' . $rekcaH;
print join ' ', map {scalar reverse} split / /, "$tsuJ $rehtonA $lreP 
+$rekcaH";
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For short variables I agree 100%.

For more complex variables, I tend to go back to concatenation to make sure I get what I want.

print "Guess what you get: $hashref->{$lookup1[$i]}->{$lookup2[$i]}\n"
+;
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Also, with syntax highlighting, punctuation actually makes the code more readable than interpolation IMO.

-- Time flies when you don't know what you're doing