When using fresh herbs check to make sure the leaves are nice and green without wilting and brown edges. Fresh herbs should be washed and patted dry before chopping. Dried herbs should not have colors that are faded. Herbs will loose their oils and flavor as they age, especially when stored improperly. When using spices, use the freshest possible.
Spices also loose their flavor with age.
Something that has been sitting in your spice cabinet for a couple of years will have little flavor left. The same applies for the use of fruit and vegetables. The brightest, plumpest, and juiciest should be chosen. Avoid fruit and vegetables with brown spots on the skin When using wine or beer, be sure it is of good quality. Dry wines are better than sweet ones.