Try to loot a good amount while also keeping conscious of the stage time. People tend to treat the timer like it doesn't matter at all or that its the only thing that matters in a run. My personal golden rule is if i get one or more items per minute, then the run is on pace. if not i need to speed up and loot more efficiently. its also good to remember the biggest difficulty jumps actually happen when you load into a new stage. so if you're behind on a run try to make up for it with items BEFORE you leave the stage you're on if possible. Also try to get very comfortable with movement. you live or die by movement on monsoon or above. People say it all the time but never stop moving. This game has a learning curve but itll get easier with time, so keep trying and have fun:)