AI'm looking for a foolproof recipe for macarons please, and also advice on the best way to flavour them please. Do you buy flavour essence or is there a better way? Thx :)

By far the best resource I have ever found for macaron production.

http://notsohumblepie.blogspot.com/2010/04/macarons-101-french-meringue.html

This recipe has been the best for me.  I was just like another recipe I had on paper that I misplaced unfortunately.  One thing it does not mention is to let the macarons sit before baking so they can get their "feet" for at least a half hour.  I have only colored or done chocolate flavor but I think the filling could be where you have fun like dulce de leche, buttercream or ganache.

http://www.heyladygrey.com/2011/02/how-to-make-macarons-step-by-step-guide.html#more

AI second the vote for Not So Humble Pie's blog. BraveTart as well. No such thing as fool proof though. Just don't plan on getting it right the 1st time, maybe you will be surprised. From what I gather, and experienced, it's better to put the flavor in the filling rather than the shell. I have had success with pulverized freeze dried strawberries or cocoa in the shell, though. I have not tried any extracts in the shell, but I don't think I personally would like it.......