Tips to customize/personalize mason jars?

I would just fill them with something edible and add a tag. Edible favors are preferable to keepsakes most of the time.

Also - there may be some other threads here you would find helpful on this subject:

https://www.weddingwire.com/wedding-forums/mason-jar-favors-opinions-please/1e9ba9dc160ee8f7.html

I wouldn't personalize them as your guests may not want to keep them with your names or dates on them. If anything, maybe the chalkboard paint or stickers and have chalk markers and guests can personalize them themselves for the night.

I don't recommend personalizing them, especially if you hope for people to take them home. Michael's and I'm sure other craft stores have those chalkboard labels - you can write something on them for the wedding but then they can be erased and rewritten and people would probably find them more useful. When it comes to favors, edible is best, most other things tend to be left behind.

I think the chalkboard labels are a great idea

That makes sense. I was on the edge of personalize and something else. Thanks guys! I'll probably do a combo of both

Michael's/Joann/Home Depot carry a great chalkboard paint by Martha Stewart and it comes in cute colors too!

Cute cardboard tags with jute ribbon filled with edible goodies