How parents usually discipline their kids today?

Most parents today don't use physical discipline. Even in the times when I was a child in the '90-s it was considered old-fashioned. However, my best friend got regular beltings from his rude father.
I am sorry to hear that your parents beat you, I hope it doesn't happen too often though.

I use my hand, but the spanking is very firm.

Some of us still use spanking as well as other tools to help raise our kids.

We have tried taking things away and grounding but it seem rather than spend time doing that and ruin the whole families day a good 15 mintue spanking works more effective

Only if you're a sick pervert who enjoys hurting children.

I was spanked as a kid, but never for 15 minutes! 30 seconds maybe?

My father last tried using physical punishment when I was 17.

After I kicked him across the room and he crawled upstairs moaning to the sound of my mother calling him a stupid idiot he decided not to do it any more.