Ok fill glass with ice pour in all the alcohol and top up with lemonade, now place in front of customer and drizzle in the grenadine for the purple rain. This is also great as a jug chaser, just double the portions into a jug and serve with their beers/wines etc and empty shot glasses, every sip of beer/wine etc equals a shot from the jug. And for an expensive party or to get a wee bit drunk ;) replace the lemonade with a sutle champagne.