Start by measuring out 1 oz of grenadine. Toss that into the bottom of the shot glass.
Take the vodka citron and measure 1 oz of it using the jigger.
Flip the bar spoon upside down just above the grenadine in the shot glass. Carefully pour the vodka citron over the spoon so that it lays on top of the grenadine.
Take the blue curacao and measure 1 oz of it using the jigger.
Flip the bar spoon upside down again, this time above the vodka citron. Carefully pour the blue curacao over the spoon so that it lays on top of the vodka.