Each of these cryptic clues has three parts:
1. A regular definition of the answer.
2. An indicator word (or phrase) that tells you this is a hidden-word clue. This can be anything that hints at something hiding, being held, being part of, being included in, and so on.
3. A string of two or more words (the fodder) that include the letters of the answer, in order.
For example, a clue for the word HIDDEN might look like this:
Orchid denizen holding secret (6)
1. "secret" is the regular definition.
2. "holding" is the hidden-word indicator.
3. "Orchid denizen" is the fodder.
Note that the three parts of the clue can appear in almost any order, but the definition will always appear at the beginning or end of the clue (as with almost all kinds of cryptic clues).