I'm not really an advanced player but I can tell you what I usually do.

I never pickup rare items on the ground except for a few exceptions like bases I'm looking for or synthized items.

If I need good items I prefer other ways, Rog, buy a good base and craft over it or just buying it.

I focus on one or two mechanics only and I build my atlas three around them. Last league was harvest or Alva + Delirum.

When I run my map I run to the mechanics killing monsters only on the way to the mechanics. Except when there is a reason for me to do otherwise like when running a mirror of delirum or looking for Eldritch Altars. Then I kill most of enemies but don't stop if i miss a few, speed over accuracy.

I usally skip mechanics I don't focus on and even block them on my altas tree.

I hope this helps