Well, if you visit System Preferences > Users & Groups, you’ll find that there’s a “Login Options” choice near the bottom-left.
There’s where you can adjust all sorts of things about how the login process works and acts. In order to make changes to those settings, though, you’ll need to click on the lock in the lower-left corner and type in your Mac password. Then let’s walk through the preferences together, shall we? This is what’s underneath “Login Options”:
In that screenshot, I’ve numbered the particularly useful settings I’m going to talk about below!
1. Automatic login. I think anything other than “Off” selected there is a security risk—that’ll mean that your computer will automatically log in to whichever user account is picked from the drop-down. That’s…um…not ideal if your computer gets stolen, so I’d suggest turning it off and then entering your account password when necessary. Note that if you have FileVault encryption turned on, you can’t enable automatic login anyhow. So if yours is greyed out, then you’ve probably got System Preferences > Security & Privacy > FileVault set up.
2. Display login window as. The second option you’ll see there will let you change your login window from looking like this (with the “List of users” choice)…
…to something like this (“Name and password”):
Why is that good? Well, if a thief is trying to guess your password to get into your machine, isn’t it best if he has to try to guess your account name, too? Just don’t turn this on without knowing what yours is, or you won’t be able to log in! Yikes. So you should know that your account name is the one that your Finder’s home folder is named after.
To log in, you can also use your account’s full name. It’s the one that appears under “Current User” at the top-left of that System Preferences > Users & Groups window.
3. Show the Sleep, Restart, and Shut Down buttons. This option (unsurprisingly) will toggle those buttons on or off in the login window.
Sometimes IT people or computer admins will turn those buttons off because, hey, why give someone an easy way to restart a machine he’s not supposed to? But I kind of feel like it’s silly to do so, as anyone who’s determined to shut a machine off can simply hold down its power button. But maybe that’s just me.
4. Show password hints. Unless you’re a really forgetful guy or gal, I think this is a good thing to uncheck, security-wise. This setting will show you a password hint if you type it incorrectly three times.
However, this is a total judgment call. If you’re much more likely to forget your Mac’s password than you are to have the machine stolen, then by all means, leave that checkbox on! Just be sure your hint is not as obvious as my example above, OK? Be a little sneaky.
5. Show fast user switching menu as. This is the one setting that doesn’t apply to the login window itself—this affects the user-switching option in the upper-right corner of your screen, which you can use to swap between accounts on your Mac if you’ve got more than one.
For that setting, you can feel free to do whatever you like. Change it to an icon instead of a name if that blows your skirt up.
I mean, I think that looks very strange in my toolbar, but I suppose it’s all right if you disagree.
Oh, and one more thing—if you’re curious as to how I got that lock screen message to appear (as shown in my very first screenshot), I wrote a tip about doing that a while back, so check it out!