Ok..bike check first…demo it then get them to do somebody elses! VITAL
attack position…demo it
controlled braking…change gear early…ie before need to…..look way further ahead than they think!
how are you covered liability wise if one seriously injures themself?…not a troll… I take newbies MTBing and they are covered by my cycling clubs insurance…not needed it but what happens if somebody crocks themself and blames you for asking them to do something which exceeds their capabilities?…clubs funding me to do SMBLA cust in case this ever happens!
Have fun, good luck but remember it's a big responsibility!