If you don't have clay cantaritos, there are several types of glasses that can be used as a substitute. Here are a few options: 1. Mason jars are a versatile and popular choice for serving cocktails, and can work well as a substitute for cantaritos. They have a similar shape and size, and can give a rustic and casual feel to your drink. 2. Highball glasses are tall and narrow, with a capacity of around 10-12 ounces, which is similar to a traditional cantarito. 3. Collins glasses are another type of tall and narrow glassware that can be used as a substitute for traditional clay vessels. 4. Tumblers are short and wide glasses that are commonly used for serving whiskey and other spirits, but can also work well as a casual substitute. Ultimately, the type of glass you use for serving your cocktails will depend on your personal preference and the occasion. As long as the glass is able to hold the ingredients and is comfortable to drink from, it can work well as a substitute for traditional clay cantaritos.