Speed

Ride on or just under the legal speed limit – where it is appropriate.
Make sure that you can always see at least two riders behind you. There is usually no need to wait for everyone to be in view. But if it is likely that they have been caught behind a slow moving vehicle, it may be prudent to slow a little, or pull over and wait if there is safe place for everyone to stop.

Marking

Consider pointing to the best place to mark the junction (from your recce).
Check the rider immediately behind has marked the last junction.

Waiting

If everyone marks the junctions, there is no need to wait at all. All the leader needs is two riders behind. One to mark the next junction. Another to take their place. If necessary, slow right down or pull over at the side of a road at a place where (say) 10 other bikers can pull in behind you.

P & T Stops

Typically 30 mins for a break, 60 mins for lunch. But that may alter. Be aware that if you make a move – everyone will assume that you are about to go.
When going back to the bike, be ready by your bike – but be the last person to mount – it stops people feeling rushed, panicking and forgetting to secure helmet, gloves etc.
Have a word with the rider who looks to be the one that will follow you – remind them to mark the exit from the cafe.

Intercoms

Modern Intercoms do not have much of a range – and it seems to be line-of sight. The MESH system works better if they remember to all connect together at the start !
If you have intercoms, check with the back marker on progress whenever you have radio contact. In an emergency the back marker may be able to contact you by phone if you have headsets and have exchanged numbers.

Backmarker

If you have radio communication it helps the leader if you let him/her know that – (eg) 4 riders are trapped at the traffic light,
– and again when you have set off.