These little 'old fashioned cream' or mini milk bottles are very in fashion right now! They look stunning with vintage paper straws and can be used to make any party look amazing. They are kind to the environment and re-usable, they can be brought out year after year for many different occasions!
You can put a little glow-stick or LED light in them and hang them from trees in the garden. You can dress your bottles with stickers relating to your chosen party theme e.g butterfly, fairy, robot, pirate etc.
For a vintage touch try adding paper doilies or doily stickers or wrap baker's twine or ribbon around them.
Consider attaching badges of your theme to ribbon around them, you can put decorative bracelets on them, and pretty hair ties, attach tags and labels with twine to them, put little blackboard stickers on them with the guests name. The list is endless.. I am sure you can think up more ideas too!
Try serving flavoured milks, colourful fizzy drinks, jelly beans or mousses in them. When not in use for the party, you can store things in them like buttons, pins or your herbs in the pantry etc. As vases on the table, as colourful lanterns again the list is endless. As well as this at the end of the party they can double as a pretty alternative for party bags that will just get thrown away, just fill them up with whatever you want, attach a thank you tag and and you instantly have a nice thank you gift that guests will enjoy and use for years to come!