[5e] Rolling treasure

I had a few questions about looting with groups of various sizes. One is specific, the other is more general and open-ended.

1. I'm about to run LMOP with 6 players and I'm scaling up the encounters. More XP will be gained, but will even out when it's divided between all the players. Should I also scale up the treasure?

2. What are some ways people like to determine loot/treasure for encounters? Sometimes I might pre-plan some specific items, but what are some good ways to make sure that people are getting stuff that's appropriate in quantity and quality for their level?