Is there a way to have EVERYBODY on the watchlist by default?

Just what I was after thanks

Another option is to set Escalations for your SLA(s) as opposed to using a Trigger (that's what I do). Of course this is specific to each Services service level agreement. Example, all my SLA(s) for a Service are configured to Escalate when due date / time is missed. This sends an Escalation notification to the Service Admin (me) and the Assignee. There also is a good amount of escalation options foe each SLA.

If those out of box configuration options don't work we can then look at Triggers. Unless you really need to add a comment. 

Seeing as you've introduced me to the wonderful world of triggers, I have decided to set up an overdue notification for the Techs. 

Iv set it up as 

WHEN > "Overdue / Not Overdue" is changed to "Overdue"

WHAT > "Add Comment" > "BLAH BLAH"

This doesnt seem to be applying the trigger when a job goes overdue (the expiry time becomes < current time)
Have I set it up right, and also would "ACTION > ADD COMMENT" also send out an email notification?

It definitely saved as I tested it and it was working. Maybe I did something stupid afterwards. Il see if it sticks this time.

Be sure to Save it and then go back in and make sure it's there. If the settings aren't saving then we may need to put in a ticket with Support. But I just tested my instance and Triggers are saving OK.

Oh...Iv gone back into trigers and its disappeared...?
Il set it back up again and see what happens

Thanks for all your help Iv got this sorted now.

No worries. I refer to it as Global Configuration because it affects all Services but it's actually named Account-Wide Settings in the Service Desk's Configure option. This is where you created your Watchlist Triggers. There is a Defaults tab under Account-Wide Settings that controls some default actions for Incidents.  

Excuse me for being dumb...but I cant find anywhere called "Global Configuration". And Our notify box is UNTICKED on every new incident so I am guessing this has been changed somewhere

'Notify Watchlisted' is checked by default in the Global Configuration. With your Triggers setup all your Users (Techs) will be notified of every single email notification sent from the Service Desk throughout the Incidents life-cycle.