It would help to know where you are traveling to. I found that not all places have ornaments year around. Google and Google Maps will help you find ornament shops. Or just walk in and look around.
I try to add an ornament to my collection everywhere I go. If I can’t find an ornament, I buy a necklace that can be used as a small ornament. Example: Vieste Italy didn’t have ornaments but a shop that made alabaster statues had alabaster pendants. The gift shop at Lipica had locally made colored glass pendants with horses painted on them.
Salzburg has a Christmas Museum with Krampus ornaments.
Lots of glass and lace ornaments in Venice.
The Christmas Shop (that’s the name) in Prague has glass ornaments.
Czech crystal ornaments were difficult to find.
Museum gift shops often have ornaments.
Naples has a street of nativity figurine shops, Via S Gregorio Armeno.
Sempre Natalie in Rome had a good selection on glass ornaments several years ago.
In Vienna, besides the Spanish Riding School gift shop, there is Andrea Cecconi.