Pour a double measure of tequila over ice in a tall glass. Add as much orange juice as you see fit and then slowly pour in some grenadine.
I like it when people ask for these because they are easy to make and there's no fruit to squeeze, nothing to shake, strain or blend. They still look goood, though. And apart from the tequila and grenadine they're really good for you.
I believe that this is a classic "prohibition" drink where bath-tub spirits were mixed with fruit juices to hide their awful taste and look not at all like alcohol.