I am taking a lot of psychology courses (second degree to be a teacher). I am also a parent to a 16 year old and a 21 year old. I have seen what works and what doesn't work.
My most important advice is to have rules and consequences not threats and threats and louder threats, which is the parenting style I see the most.
I just did a quick google search that explains this:
There are almost as many parenting styles in the world as there are parents. However, most experts have classified parenting styles into three main categories: authoritarian, permissive and authoritative. If you are aiming to raise a self-reliant, pleasant, well-behaved child, The authoritative parent will generally have the most success.
What is Authoritative Parenting?
Authoritative parents exercise control over their children, without being controlling. They set rules and guidelines that they expect children to follow. But they also recognize that sometimes flexibility is called for. Authoritative parents often express love and affection to their children, without fear that such expressions of emotion may affect their ability to discipline. As their children get older, authoritative parents encourage more responsibility and freedom, within well-outlined rules. The American Academy of Pediatrics and other childrens health organizations state that children of authoritative parents usually grow up to be independent, socially successful, and respectful of authority.
Using snacks as an example, an authoritative parent might allow sweets in moderation, after explaining to the child that such treats are tasty, but not necessarily healthy.
Authoritarian Parenting
Like authoritative parenting, authoritarian parenting involves control. But unlike authoritative parenting, authoritarian parenting usually involves too much control. Authoritarian parents set rules and standards without flexibility, emphasize obedience and feel it is important to exert power over their children. Authoritarian parents may not show as much love and warmth as authoritative parents, which can lead to their children feeling rejected and unloved. Authoritarian parents are also more likely to label a child as bad if they fail to follow the strict rules set down for them. Children of authoritarian parents usually follow one of two paths; they either rebel against authority and escape their homes early (whether they are ready or not), or they remain dependent on their parents throughout adulthood.
Again using the snack analogy, an authoritarian parent would set a rule that sweet snacks are never allowed, no matter what the occasion.
Permissive Parenting
On the face of it, permissive parenting may seem like a much better idea than authoritarian parenting. Permissive parents show lots of love and affection, accept their children for what they are and make few demands of their children. But in doing this, permissive parents fail to teach their children the consequences of their actions, respect for authority and responsibility. By showing little or no control over their children, they risk raising a spoiled child who expects to be spoon-fed both physically and emotionally throughout life. Children of permissive parents are less likely to grow up independent and socially successful than children of authoritative parents.
In the snack example, a permissive parent would not limit a childs intake of sweets, and would not explain the consequences of unlimited snack consumption.
Authoritative Works for All Children
Since authoritative parenting is inherently flexible, it works for all kinds of children. Whether a child is naturally anxious, easy-going or energetic, authoritative parents know that they can deal with any problems that arise as long as they stay firm in both their love, and their authority. Authoritative parents recognize that not all children are the same, and that rules may need some changing depending on the child. Being a flexible, authoritative parent shows your children the value of compromise and lets him or her know that while you are still in charge, you can make changes in rules if necessary.