These ideas for packaging jam and other preserves would be great for gifts, they use vintage jars with labels using a simple font.
Vintage jars can be picked up in charity shops and flea markets, just make sure to carefully clean and steralise them before using.

If the jars don't have lids they can be sealed using waxed circles which, when placed directly onto the surface of the warm jam, create an airtight seal. The jar can then be finished off with a decorative paper jar cover.

Le Parfait jars are great for using when preserving, as their rubber seal and clip mechanism ensure a perfect airtight seal. They can often be picked up cheaply second hand and with a bit of cleaning and reconditioning come up as good as new.

Le Parfait are French jars which have been designed specifically for canning and making preserves. Their thick glass enables them to withstand boiling in a water bath during the canning process.
I also find them useful for when you want a presentable looking jar, rather than a reused jam jar, or if a good seal is essential, as during all the shaking while making sloe gin.