Tonal difference between 浪费 and 糟蹋
糟蹋比浪费的语气更强烈。人们觉得很珍贵的物品被损坏或不被爱惜的使用了，通常是用糟蹋，而不会用浪费来形容。粮食可被浪费，可被糟蹋；人才可能被糟蹋，无法被浪费。

浪费：较为便宜的物品被损坏或不被爱惜的使用了，说话者觉得可惜但不心痛，会使用浪费这个词。
糟蹋：很贵重的物品被损坏或不被爱惜的使用了，说话者有心痛的情绪，才会使用糟蹋这个词。

糟蹋 has a stronger tone than 浪费. When people feel a valuable object is being damaged or is not being used with care, one would usually use 糟蹋, and not 浪费. 粮食 can be 浪费 or 糟蹋; 人才 could be 糟蹋, but is unable to be 浪费.

浪费: use when a relatively inexpensive object is being damaged or used without care, when the speaker feels it's a waste but not in a painful way.
糟蹋: use when a very valuable object is being damaged or used without care, or when the speaker feels pained.