Using Top and renice

When you are running a server that have more than 1 user competing for the limited number of resources, how do you prioitise the run manually?

I use top to check who is hogging the resources and I use the command

# renice +5 -u peter
# renice + 5 -p 8765

It helps alot. But I prefer the htop to influence process directly. See Using htop to influence processes directly