Martinis

Ok ... why does a martini cost so much in a bar?  It is only gin with a bit of vermouth (more on that later) and it is classified as a "cocktail" ... wow not much work sticking in 3 parts gin with 1 part dry vermouth and stirring it round with ice (yeah, I know the barkeep says it's two slugs of gin but how often do they just dilute it with the melted ice to fill the glass).  

I prefer to keep the gin in the freezer and the vermouth in the fridge ..then no ice and that means no water and that means no dilution. So, stronger flavours but also faster licence loss or messy guests (very). 
The classic (in the olden days) martini was the two alcohols poured into a jug (often without ice) and mixed around and served into a nice glass and topped off with an olive or a twist.
Yes you can use vodka instead. 
And you do not need to use some fancy expensive gin or vodka.  Gordons has a great juniper flavour that really makes a martini. Sometimes I use Tanqueray or even Bombay but it depends on the flavour I want. 
Recipes? Try adding a twist of orange peel instead.  Or if you want a dessert martini wash the glass with Grand Marnier (on that theme ..I will post my secret Martini Royale recipe here soon!!!). Make it a Dirty Martini by adding a spoonful of olive water with two olives. That one works with vodka or gin.