Below are my go to's for HGEs, I am successfull 60% of the time.
Imperial Shielding: Best for trading because not contaminated by grade 4 mats.
Tchernobog
Hruntia
Core Dynamics Composites and Proprietary Composites
Wolf 562
I save stupid multi-taskable stuff to do when I do them like paperwork or going through emails. Use collector limpets. When the last mat is scooped immediately go back to desktop then login. When in game immediately go to nav panel and find nearest unidentified signal source and charge up fsd. When the count 4321 begins immediately throttle down so that your distance from the HGE USS is shorter.
Crashed Anaconda site: Raw materials in Bubble: Antimony, Tellurium, Ruthenium, Zirconium, Tungsten
Koli Discii 6 A (the planet with Gerlache Base)
It's 95,000 ls from main star, BUT... Upon being within 1000 ls of the planet the crashed ship site appears on the nav panel - no futzing with latitude and longitude. Also the site is pretty flat so SRV driving is less nauseating. I do the dishes and housework during the 13 or so minute supercruise. Crystal shard sites are better but I can't be arsed to do that much jumping because I am jumping challenged.
Selenium is Prthi 2A? can't remember exactly which planet. Have to use SRV
Molybdenum and others. Trus Madi, Todd the Blaster's planet has pretty good drops, too. Also SRV