Seven key steps to cook up a sample size -- Sample sizes for parallel group superiority trials with normal data -- Sample size calculations for superiority cross-over trials with normal data -- Sample size calculations for equivalence clinical trials with normal data -- Sample size calculations for non-inferiority clinical trials with normal data -- Sample size calculations for bioequivalence trials -- Sample size calculations for precision clinical trials with normal data -- Sample size calculations for parallel group superiority clinical trials with binary data -- Sample size calculations for superiority cross-over clinical trials with binary data -- Sample size calculations for non-inferiority trials with binary data -- Sample size calculations for equivalence trials with binary data -- Sample size calculations for precision trials with binary data -- Sample size calculations for clinical trials with ordinal data -- Sample size calculations for clinical trials with survival data.