Place lime and sugar into thick bottomed rocks glass,(if you don't have one use glass part of Boston shaker) and muddle with muddler for one minute
Add Vodka and stir with barspoon, taste and adjust tartness or sweetness, but keep in mind that once the ice is added the taste will be slightly weaker (transfer to drinking glass if using Boston shaker).
Crush ice with ice crusher and fill glass halfway. Stir, then fill glass with ice and stir again.
Drink :)