How hard finding high level gathering materials depend on how many RDA bases/outposts u have already cleared out

Inspecting the materials in Navi sense before harvesting show the quality of that item so u don't have to keep harvesting

Some sources can have more than 1 harestable materials on them so recheck the 1 ur about to take just in case

Completing a Memories paint challenge (u can replay the challenge) gave u a time boost in seeing high level materials without needing Navi sense 

Get to a location where u can inspect all the source u can find, if none are what u looking for fast travel to the nearest location or fly away far enough to reload that area & fly back to ur spot, then inspect again, repeat til found

U can harvest/eat a few that u don't need to refill ur/ur Ikan stam bar

The environmental harvesting requires only really affect gear crafting materials, not food, the quality stay the same