In a flash memory device, different self-boosting techniques are selectively applied to a string of serially connected memory cells responsive to a programming voltage applied to a selected word line. For example, non-local self-boosting and local self-boosting may be selectively applied responsive to the programming voltage applied to the selected word line. For example, non-local self-boosting and local self-boosting may be selectively applied to a first string of serially-connected cells responsive to the programming voltage during an incremental step pulse programming (ISPP) of a selected cell of a second string of serially-connected cells.