Always make sure that your child is strapped in safely, in a suitable child restraint, ideally in the rear of your car - even on short journeys. 
Check that the child seat is fastened securely and that the harnesses are adjusted correctly. Never use a rearward facing child restraint in the front of a car with a passenger airbag.

Load heavy pieces of luggage at the bottom, lighter ones on top and spread the load. Do not load luggage above the height of the rear seat. Make sure that all luggage is stowed safely and secure heavy loads to the base of the boot. If there are no passengers in the rear seats, fasten the seat belts, if possible, crossways, to give added stability to the back seat.

Make sure that the top of the head restraint is as high as the top of your head, and as close as possible to the back of your head. Adjust your seat to provide good support.

Always wear a seatbelt and ensure that every occupant of your car, whether they sit in the front or the rear, uses their seatbelt for all journeys.