HI.
This may be a stupid question, but which method do i use to report people who just crash on purose for the sake of trolling us or to try and gain an advantage from it ?
Do i just use the regular xbox reort player function, or is it done on a section of the forums? Do i also need to record an upload clip of them caught in the act or can the servers recognise it
automatically through magical witchcraft haha 
Many thanks for your time & sorry if im being stupid & overthinking things .
Use the Xbox One method of reporting this game-disrupting behavior (poor sportsmanship) by going into Friends in the Dashboard, then Find the gamertag and REPORT the actions. Those reports go to the Xbox Live Policy Enforcement Team (PET) and they have the capabilities to join offenders during their online sessions for observation and warning.
Not only will those incidents result in PET taking actions, but they have the power to instantly ban those who challenge what they warn about - not just from the game itself but Xbox Live. That really gets the attention of people who are destroying game play for others.
Don’t get into discussions with the offenders, just observe, remember the gamertag and file the report. Let PET handle it without attempting to tell the offender how wrong they are or using retaliation. It is simple and effective when PET puts a leash on the crasher.
Remember, too, when PET issues a ban on a gamertag, it isn’t just for a single game, it is a time out from Xbox Live.