I've been making cosmos since Sex in the City introduced it to me. I've had really bad ones and really good ones. The trick to this is fresh lime juice and not too much cranberry juice. It should be a pale pink color and if you order one that is red then you will probably not like it. I find it taste too chalky and might as well be a vodka cranberry. You don't have to rim the glass with sugar but I like to make mine a little more tart so I enjoy the extra sugar with each sip. Try this and let me know what you think.
1 1/2 ounce vodka
1 ounce fresh squeezed lime juice
1 ounce triple sec
1 ounce cranberry juice
1 tablespoon sugar (optional)
Before making the cocktail put martini glass in the freezer. In a shaker add first 4 ingredients plus a few ice cubes. Remove glass and rim it with lime juice and sugar. Shake your cocktail rigorously to get a nice froth. Pour into glass and serve. Makes one at a time.