TWRP: What should I select in Backup on OnePlus 5

I'm new to TWRP and I'm going to be installing a custom.ROM/Kernel. I've messed up my device a few times by installing random things. I've fixed it now, and I'd like to start making backups. I know that the OnePlus 5 has dm-verity and I've heard that dm-verity prevents some backups. What should I select in backup in TWRP for the OP5?