Time-outs are not hard to do, once you begin to do them over time they will get easier and hopefully non existent.
If your child is doing something wrong such as swearing, not doing as they are told, etc then take the first step which is coming down to the child's level.
For older children, you don't have to come down to their level as you would to a two year old, but as long as you are looking at them in their eyes and they are looking at you.
Give the child a warning
This is your first warning, you are not to climb on the table" as an example.
Walk away after you have warned the child. If you stick around, or keep holding onto them then they will get aggressive and angry. Walking away lets the child get back to behaving or doing what you told them, which would be getting off the table in this example.
If your child does not listen after you have warned them then you can step in. Give them a reasonable time limit, example:
Warning a child to clean up a mess they have made, walk away to let them do the task. If they haven't attempted to start within the first two minutes then move forward.
If your child has not listened to your warning, go back in and walk them to your time out spot which may be a corner, a chair or a room.
Place the child in the time out spot, and explain to them why you have placed them there.
"I have put you in time out because you did not listen when I asked you to get down from the table, you will sit in time out for 5 minutes" - example.
After you have said this, walk away and don't listen to any remarks that the child screams out (which they will during the first few time outs)
If the child gets up from the time out, walk them back each time. Don't talk to them, as talking and conversation will only make it worse. Don't look at the child when you put them back, once you put them back walk away, don't stick around or stand at the corner in case they get up again. If you keep placing them back without talking they will realize no matter what they do, they will still be put back in time-out.
Once the child has done their time, go back and ask them why you put them in time out.
"Why did I put you in time out for?" - example.
If the child doesn't want to answer, tell them again. Get them to apologize, give each other a kiss and cuddle and then move on. Don't bring it up again, but if the child still is crying, screaming, swearing and acting sooky because you put them in time out, if they don't calm down warn them they'll be staying in time out longer. Wait a few seconds and if the screaming persists, walk away and let them stay in the time out corner.
Time out's don't need to be hard, upsetting or stressful. Of course at the beginning they will be, but if you remain positive that things will get better then your time-outs will improve.
Always remember that any slip ups during time outs including not giving a proper warning, talking while taking them back to the time out area, etc will unravel all your hard work. Stick to the steps and you'll have your children behaving way better.