Here are the basic steps for how to rim a cocktail glass. Read the post for even more fun and unique ideas and variations so you can create a fun rim for all your mixed drinks.
Liquid to moisten the rimLike water, lime wedge, chocolate syrup
3tablespoonssalt or sugaror crushed graham cracker as shown in the post
Instructions
To a small shallow plate, add salt.
Use a wedge of fresh lime juice and run it around the rim of a cocktail glass to moisten it.
Dip the wet edge of the cocktail glass into the plate of salt.
Rotate the glass to cover evenly or choose just one section.
Gently shake excess salt off.
Set aside prepared glass until the cocktail is ready for serving.
Notes
You don't have to rim the whole glass. You can wet just a section, even down on to the side of the glass a bit, and place the salt/ sugar/ etc. in just one area.
Be creative with what you use for the liquid. You can use water, lime, lemon, orange, simple syrup, honey are all things you can use to moisten a glass.
Look for things to rim the cocktail glass with that aren't super heavy (like a red hot candy, for instance) as they won't be able to stay on the glass.
See the post for the full instructions for rimming a glass with lime and salt or Tajin, water and sugar and chocolate sauce and crushed graham cracker.