I pack for both of us, always! Mr LP is slightly colour blind, so I would never trust him to pack for me.
I am a list maker, and I have a spreadsheet for holiday packing. This includes separate lists for our clothes, and what I call the "other" things - toiletries etc. The spreadsheet is updated after every trip, and items added or deleted. Separate lists for hand luggage.
The cases come downstairs and are put in the snug 1 week before we travel. I then pack at leisure over the week, checking off the list as I go. Like other posters, I pack half our clothes in each suitcase, just in case.
I have a countdown list in days, as to what needs doing before we go - hairdresser, cleaning, birthday cards to post, charging kindles, changing currency etc.
Take enough meds for however long we are away, plus an extra week - so glad of this when our return flight was delayed one January because of bad weather in the UK, and we spent 2 days at a hotel near to the airport. Always take copies of repeat prescriptions.
I do suffer with holiday anxiety, so having these detailed lists calms me down, as I can see what I have packed.
Mr LP is in charge of booking flights, accomodation ( once I have chosen it!), car parking at the airport, and anything technical.
It works for us. We're due to go away in May, first time away anywhere since May '19, so my packing skills may be a bit rusty!
Take care xx