Not normally my kind of thing, but I’ve just tried a few to be sure.
If you say “Hey Siri play the playlist”..... and then the name of the playlist you want it’s worked for me every time. Even when I mis-pronounced a couple of names
I did put a big list of Siri commands on another thread, I’ll see if I can dig it up for you.
*Edit*
Here’s a quick rundown of some of what I consider to be the most useful things. Maybe you’ll find some useful.
You can restrict who gets to use AirPlay by choosing from Everyone, Anyone on the same network or Only people sharing this Home. This can be accessed from the first tab of the Home App, by tapping the arrow in the top left. You can also update the speakers software in here.
You can tweak how HomePod works to some degree by opening the Home App and Force Touching the icon for HomePod then selecting Details from the bottom right of the screen.
In here you can for instance, turn off the HomePod display or add an audible beep so you know that you’ve invoked ‘Hey Siri’ properly and it’s listening.
If you have kids and don’t want their delicate little lobes unexpectedly bombarded by your classic NWA collection, you can turn off explicit content.
You can also turn off the listening history in here, so that your personal recommendations aren’t affected by said kids repeatedly playing whatever that damn song from Frozen is.
Open up Control Center on your iOS device and expand the audio widget. There you'll see a separate entry for the HomePod. Tap on it and it takes you into Apple Music, using the iPhone as a remote.
As for the “Hey Siri” commands, You can do things like setting the volume level exactly by saying ‘Set volume to xx %’ instead of just invoking the up and down volume commands.
You can get songs you barely remember by saying, for example, ‘Play that famous song from The X Files’
As well as being able to play songs by mood or genre individually, you can also mix and match these up. So instead of saying ‘Play some Chill music’ you can say ‘Play some Bedtime Chill music’ or ‘Play Upbeat Party music’ and so on.
Add a song to a playlist by saying, yeah you guessed, ‘Add this song to my xxxxxxx playlist’
Send a text/iMessage by saying ‘Hey Siri text xxxxxx’ (You can also use WhatsApp among others).
We know HomePod, annoyingly, can only do one timer. But as a workaround for now just use reminders by saying ‘Remind me in xx minutes to do xxxxx’
Another alternative to the one timer situation is to use Alarms instead of Reminders, as you can have multiple Alarms on the HomePod too. Which makes the timers situation all the more bizarre.
Anyway, you can either say;
‘Set an alarm for xx minutes time’ or
‘Set an Alarm called xxxxx for xx minutes time’ or of course
‘Set an Alarm called xxxxx for xx:xx hours’
and it works much the same way.
To further enable/disable/delete/add/edit Alarms on the HomePod manually, go to the Home app and force touch/long press the HomePod icon and select Alarms from the bottom left of the screen.
If you play a song and it’s not by the artist you were expecting, just say ‘Play a different version’ to hear it from an alternative artist.
If you’re listening to things like the News and getting bored, speed things up by saying ‘Play Faster’ Likewise you can say ‘Play Slower’ to take things down a notch.
If you want your iPhone/iPad to be the device which responds to your requests, as HomePod will almost always be the default option if it can hear you, you either need to raise to wake your device, or hold the button to activate Siri on your device first.
Other commands for "Hey Siri" when you're listening to music include:
‘I don’t like this’,
‘Don’t play this again’
‘What song is this’
‘Who sings this’
‘When was this released’
‘Play more like this’
‘Make a station from this’
‘Add xxxxx to Up Next’
‘I like this’
‘Play the playlist xxxxxx xxx xxx’
‘Play the album xxxxxxx’
‘Play songs by the artist xxxx xxxx’
‘Play the new album by xxxxx xxxx’
And there’s always the trusty ‘What can I say’ command which will prompt Siri to tell you some things you can do, you can do this more than once for different answers.