I. When to use "the"
When to use "the" before a noun modified by a prepositional phrase or a relative clause?
Consider this explanation, which can be applied for OP's case :
When using the article “the” in English grammar, remember that there are different ways to use it.
Use “the” to refer to a specific noun that is known to the speaker.
https://promova.com/english-grammar/when-to-use-the
II. Use of "the" for a modified noun.
In simple words:
We use the definite article when both the speaker (writer) and the listener (reader) know which item is being referred to.
Consider these sentences with and without the definite article.
(1a) She likes to read detective novels written by Golden age authors.
(1b) She likes to read the detective novels written by Golden age authors.
Explanation:
(1a) is more general, while (1b) implies a specific selection of detective novels..
(2a) They order food online from restaurants that have good reviews.
(2b) They order food online from the restaurants that have good reviews.
(2a) is general, while (2b) suggests a specific list of restaurants with good reviews..
Consider OP's sentence and argument for not using "the"
These disciplinary techniques could range from depriving children of ____ things they treasure, such as their favorite toys or TV programs, to...
Nevertheless, this argument could be seen from the opposite angle; is they treasure specific enough to make the compulsory? Children treasure a lot of different things.
If you think "things which children treasure" are vast and cannot be specified by mentioning only favourite toys or tv programmes, you are justified in omitting "the".
- Omitting "the" implies that the things children treasure are varied and not limited to specific items like favorite toys or TV programs.
- Including "the" would suggest that the things children treasure are specific and well-defined.
Edit-1.
OP's sentence in the comments
"I don't like the flowers you bought.".
In this case, the speaker and the listener are aware which flowers are being referred to, so "the flowers" is the only choice.
If the speaker doesn't like some of the flowers, the sentence becomes:
"I don't like some of the flowers you bought."