Limits in what a parent can instruct their children-Not to overburden one’s child with demands and to be forgiving of one’s respect:
It is forbidden for a parent to overburden his children with demands and to be overparticular with their respect towards him, in order so he does not cause them to stumble. [According to the above, a parent should not make a request from his child if he knows that it will be most difficult for his child to fulfill it and will cause him much pain. A parent who knows or assesses that his child will not listen to his instructions and instructs him anyways to fulfill his wishes, transgresses the prohibition of Lifnei Iver the moment that he gives his instructions. This applies even if the child does in the end comply with the request.]
Forgiving one’s honor: Rather, a parent should forgive [his honor] and ignore their disrespect, as a father who forgives his honor, his honor is forgiven. [This applies even if the child was not made aware that his father forgave his respect and hence it is recommended for a parent to forgive his respect even without the knowledge of his child in order so the child not get punished.] See Chapter 1 Halacha 6 for the full details of this matter!
Treating one’s adult children similar to colleagues and brothers:
Some Poskim write that for this reason a father should treat his older children similar to brothers and colleagues and speak to them with calm and patience and this will help one have a good relationship with his children.
Advice for parents whose adult children don’t always listen to them:
In the event that one’s adult children don’t always listen to the parents request, often it helps if one speaks to the friends of the adult child to speak with him and try to influence him in the direction of the parents. Experience shows that friends of the child can have much more influence on him than even relatives and parents together.
 Michaber 240:19; Tur 240:19; Rambam Mamrim 6:8; Kiddushin 32a; Sefer Chassidim 565; Encyclopedia Talmudit Erech Kibud Av Vaeim Vol. 26 p. 429-430; Pesakim Uteshuvos 240:52
 See Tosafus Avoda Zara 6b; Machaneh Chaim 1:47
 Sefer Chassidim 562; See Tosafus Sanhedrin 63b; Rosh 7:3; Chofetz Chaim Hilchos Lashon Hara 9:1; Chazon Ish Y.D. 62:13
 Yad Malachi 367; Yitzchak Yiranein Hilchos Talmud Torah 6
 Sefer Chassidim 152; Shiyurei Kneses Hagedola Tur 240:38; Kiddushin 32a “Rav Huna tore a silk garment in front of his son Raba Bar Rav Huna in order to test him to see if he would get angry. He did so when his son was already angry over another issue. By doing so, he did not transgress the prohibition of Lifnei Iver being that he had already forgiven his honor. He likewise did not transgress the prohibition of Bal Tashchis being that he tore it in an area where it would not lose any of its value.”; Tosafus and Ritva ibid; See Yosef Ometz 87 and Teshuvah Meahava 370; Encyclopedia Talmudit ibid footnote 774
 Bris Olam on Sefer Chassidim 343 as can be learned from Scripture which states that Yaakov treated his sons like his brothers
 Likkutei Sichos 22:435