Yes these are the tips to handle your child well. I do face this problem once  a while, but I make it sure that I don't loose my temper.I have observed that if I manage my son in a little tender way, his aggressiveness reduces. Moms have to play the role of friend too, I may be as strict, but the kids do share every thing with me instead of their pop.

I think as the adult/parent in the relationship we have a lot of responsibility to set a good example, and lead  by example.  I think that it's very easy to be so caught up in our worlds (the stresses of work/family etc) to not realise that we are in fact taking this out on children.  Losing your temper with a child is never a good thing.  They can understand that they are in trouble or have done wrong, without them being on the receiving end of your anger.  Raising your voice doesn't necessarily mean that you're angry, there is a difference.  But if you discipline a child with anger, that child may respond with anger.  They see that it is fine for you, so do the same.  Not everytime, but well.. that's just my theory. 

When dealing with aggressive children we must always try to find out the reason why they behave that way , only after knowing their motives we can find the right way to aproach him or her ( oh,yes, girls may be aggressive ,too! ).

If the child's aggressivity has to do with things happened outside the house ( in school ,kinderschool ,or in  neighborhood whle palying with other kids ) the best thing is to help him clarify his feelings ( he may just feel that was treated unfair and his aggressiveness is a way to express that) and to see the positive side of everything , making him /her capable of understanding others point of view in the same time . If the child acts aggressive as a response to your raised voice and/ or emotional or physical abuse ,then you must apologize to him/her for losing your temper,calm down and explain to him/her that you're not perfect and can make mistakes  ,giving him an example on how to act when he does wrong .