Hi,
Moving house, Schools, Parenting homes, holidays and independance transitions are a few I've come across.
Not sure transitional needs change so much through the ages maybe just the 'age appropriativity of things - Preschool soft toy may provide comfort and reassurance for littlies whilst home telephone & contact details for a teenager may provide the same reassurance of backup.
Staying safe strategies, who to turn to in an emergency and where to find them - open times, schedules and staffing information.
Unfamiliar territory - Finding your way a new building, home or school.
Tours, induction days and 'getting around visits - Maps
The PDF available from NFER is good:
How children make sense of the transition to Year 1
Source: National Foundation for Educational Research
Nursery to Reception case study from Teachernet :
Improving transition strategies – nursery to reception
Secondary
School, Peer mentoring programme. Hygiene, health, the law & where to get advice, help & product information from..
Other strategies that I've come across on the net
Friend, Buddy and other mentoring strategies to help support unfamiliarity and confidence.
Maintaining & including familiar routines.
Adult approachability and involving the children in decision making processes.
Assurance and explanation.
Hth xx