Thank you for the comments so far. Please let me summarise what I think you have all said.
1. If you don't have a smile and a genuine welcome, the rest doesn't count.
2. Have visual aids, clan specific if possible, eg photo of clan castles, etc
3. Have things people can tactilely engage with, eg helmets, targes, kilts, etc
4. Have reference material, eg a clan map of Scotland, tartan book, clan book listing septs, etc
5. Demonstrate hospitality, eg a cup of tea, a piece of tablet, a wee dram, etc
6. Provide props to create photo opportunities

Is this what attracts and engages people at clan tents? If one couldn't do everything, is this the priority order?
Are these the things that clan tents are judged upon at Gatherings?