Cook the macarons the day before you want to serve them so they have time to break down a bit and become soft and chewy inside.
Be careful not to over-mix the meringue or to overwork it when folding it into the almond mixture.
It is vital to leave the uncooked macarons to rest so they form a skin – if you put them in the oven too quickly, they will crack. Resting is also key for creating the signature ‘frilly’ bottoms of the finished macarons.
Don’t mess with the flavour of the shell – put the flavour in the middle instead.
Don’t under-fill the macarons or they will be too dry.