mac maintenance

my free disk space is getting too small
and i am trying to put more effort on the maintenance

could you guys tell me what you do to keep your mac neat and clean?
such as what files in which folder are unnecessary and such

Also, i found 'drive genius', 'leopard cache cleaner', 'macdust' and 'cocktail'
do you guys use any of these apps? are they any good?
what app do you guys use yourself for maintenance?

Thanks so much!!

Firstly, establish what files are taking up all that room, then you can figure out what to keep, what to delete and what to archive

Disk Inventory X

If you are comfortable going into Terminal and root, download a free application called Applejack, read and print the instructions upon install. To use start up in single user mode and run the program.

There is also a deep cleaning option. Also consider a larger HDD and using the current drive externally in a case, connecting via firewire.

Download AppleJack for Mac - Troubleshooting/repair utility. MacUpdate Mac System Software Downloads

1. make sure your iPhoto trash is empty
2. if one type of file is taking up loads of space, it is likely video. go through video files and see whats worth moving to another computer/drive
3. i personally think that as long as files are stored in appropriate places, then drive management software is unnecessary... meaning there are files somewhere that you have knowingly or unknowingly added which are consuming this space.