Best: for me is least expensive to keep shipping cost down for buyer.
I’m not selling collectibles, so I can keep it simple, and keep shipping costs down, nothing fancy: lp in it’s sleeve, in a box. watch your unit price, look out for excess shipping costs
here’s .60c each, free delivery (add tax).
https://www.amazon.com/Kshioe-Record-Shipping-12-5in12-5in1in-Mailers/dp/B092J3NWBD/ref=sr_1_23?hvadid=616863247803&hvdev=c&hvlocphy=9003512&hvnetw=g&hvqmt=e&hvrand=12482783388837832379&hvtargid=kwd-4766850229&hydadcr=24634_13611738&keywords=vinyl%2Brecord%2Bmailers&qid=1680521046&sr=8-23&th=1
They fold, either 1/2" or 1". Typically: just 1/2/3 lps Inside: I use usps priority mail stiff envelopes tripled over. like a spring, to take up the extra inside height, cushion the lp/lps if only a few. fed ex letter envelopes the same, any stiff cardboard that can be rolled to be like a spring.
Recently I sent 100 to one nephew, 50 to the other. You can fit 8-10 lps in the 1" height, tape em tight, they all arrived safely.
If BEST means best method/protection for collectibles, that’s a whole different category of box.
I buy albums from Amazon, and the boxes they use are very protective (new lp with lp in the sleeve), I save the boxes. Others, remove the vinyl from the sleeve, add new static free liners, ...