How can I tighten my bike handlebars to ensure they are secure and safe for riding?

To tighten your bike handlebars, first locate the stem bolts on top of the handlebars. Use an Allen wrench to tighten these bolts in a crisscross pattern until they are snug. Make sure the handlebars are straight and at a comfortable angle before tightening fully. Test the handlebars by trying to move them side to side to ensure they are secure and safe for riding.