Voice, signals and whistle – in varying tones and volume i.e. make your whistle talk too!
To be preventative – how to penalise without having to blow the whistle
To allow the game to flow – within acceptable parameters – ATP – Ask, Tell, Penalise – the ask is often in the pre-match briefing
To be approachable but not gullible – Captains only - not open forum
To maximise downtime to help get your message across, reiterating the points made in the pre-match briefing
To be firm and calm

Scrummage:

Get them level
Crouch – Touch - Pause – Engage. It’s your call, not theirs
Keep them a suitable/comfortable distance prior to the above
Square and stable – they must be comfortable too
Full arm bind and attached 'til the end
Backs 5m away 'til ball is out

Lineout:

Has it formed?
Two straight lines with a clear space
The thrower – behind the line. The throw without delay – the jumpers wait til it’s in.
A fair contest – priority anything untoward across the line!
The threes back 10 til it ends

Tackle:

Get there/Be first there to see … then move to get the wider view
The tackler to release the tackled man and roll away
The tackled man to be free to place the ball as far back as possible and roll away
All other players to arrive and stay on their feet
To arrive through the gate

Ruck and Maul:Know the difference and call it

Check on those joining and then those outside
Call “Ruck”
Call “Maul”
Having got there and seen it – move to get the wider view

Advantage:

The best law in the book:
Where is it on the field of play? Close to the non-offending goal line, midfield, close to the tryline?
What’s the offence/issue – knock-on, therefore scrum or penalty kick?
Tell them - Scrum advantage; penalty advantage; advantage over
Talk to them – signal to them – the key players need to know
Tactical or territorial – wait and see. The class referee always has time!
Don’t call them back – bring them back

There is a difference between empathy and sympathy. The former is the trait of a good referee; the latter shows weakness.

Fitness is both physical and mental – without the first the second becomes a struggle.

Make your own checklists – use these. Go through them when training, when warming up, when pre-match briefing, at the next situation – tackle, maul, ruck, scrummage, lineout, kick, injury, etc.

I hope the above will help focus your mind on the key issues. Physical fitness and speed of thought and reaction go hand in hand!