What kinds of things should I do to maintain the performance of my iMac? I've recently switched from PC to Mac. So far, so good!

With my PC, I had a variety of tasks I'd regularly perform to keep my PC running well:


Run CCleaner to clean up all the cruft (temporary files, hidden caches, etc.) that browsers leave behind
Run CCleaner to clean the registry
Run AdAware to clean up tracking cookies, etc.
Run MalwareBytes malicious software removal tool
Run Microsoft's malicious software removal tool to backstop malwarebytes (hoping that at least one of them would find the hard-to-catch stuff)
Run MacAfee's virus scanner (This software never did anything but give me headaches. But it's popularity made me uncomfortable just deleting it)
Run a disk defragmenter


There's probably a few more I'm forgetting too.

Obviously, PCs are high-maintenance. Maybe my list was overkill - I tend to do that, but since I use a computer to make a living, I want it to perform as well and reliably as it can.

So, now I use a new iMac. While I'm hoping the list is shorter than the PC list, is there anything I should do to keep it performing optimally?
Set up Time Machine the first time you start you Mac,
Set up Software Update so that your system is always up to date.
A shutdown once in a while should clean most of little garbage but you will have to perform it anyway with some software updates.


and


Never log in with administrative privileges unless you have a serious reason to do so.