Most of the time, you can purchase the batteries already connected, but if you don't, you will need to solder them together.
Titanium is most commonly used for rings because the hard metal is difficult to solder or mold into intricate shapes or to engrave because laser engraving is the only type of engraving method that works well on titanium.
These do-it-yourself kits are available in a wide variety of types, and each kit includes everything you will need to complete the job including solar cells, solder, soldering iron, flux, and all necessary connections.
Solder was extremely expensive and so tinsmiths often used small spots of solder to attach the handles rather than a larger area of solder.
Look for a wide assortment of stones and beads, as wells as pliers, solder, and other tools for making your own jewelry.