In case your family members have not got adjacent seats during automatic seat assignment then make a humble request to other travellers and try for seat exchange so that all of you can sit together.
Keep good collection of your favourite songs in your cell phone or mp3 player. Also do not forget to carry your earphone with you.
Bus journey gets more comfortable in large groups because you spend your time in talking to your known ones. Hence if possible try to get people along with you during bus journey.