The Autism Education Trust has a Transitions Toolkit which although written for teaching staff seems to provide some useful tips on dealing with transition periods. It would also be useful to direct staff to if you feel they are not doing enough to help your child. Here's the link. They also have some resources which you may be able to use at home, here.
There is also some advice on the National Autistic Society website, here.
Aberdeenshire Council do have a transition programme for children who staff feel may benefit from extra help. As far as I'm aware this programme is still running.
I will look into working on some resources of my own - star charts, emotions fans, timetables and mini award notes, etc., and upload them soon. Any ideas to add to this, just let me know.