I use a kind of modified
faro shuffle to shuffle my cards. This ensures pretty thorough randomizing. I also will pull out a small group from the deck (5 to 10 or so cards), reverse them and lay them on the top, or the bottom (depending on what "feels right") between shuffles. My modification is that I lay both halves of the deck face down on the table and start from there, instead of holding them entirely in the hands (as the video shows). One of these days I've got to make a video of how I shuffle - it's much easier for handling these large decks.
(Notes; if you're going to learn to do a faro shuffle - learn and practice on regular playing cards or a deck that can be easily replaced! There is a potential for damaging cards when you're learning. Also, be cautious when doing a faro shuffle on very old decks - I split a card in my mother's old Albano-Waite deck. New decks can be problematic as well until the edges get a bit of wear on them.)
Having said all of that. I do not bother re-ordering my decks unless I'm going to be studying them. After I do a reading I put the cards into random places in the deck, then do 2 or 3 shuffles as I already described. When I'm ready to do another reading, I will do 3 or more shuffles (depending on what feels right), then let the client cut the deck. I am reluctant to let clients shuffle - for starters, most people try to riffle-shuffle the decks which bends the cards opposite from what I do. Also, the vast majority of people are not used to handling large cards or decks with more than 52 cards, so there is potential for cards going everywhere, or being damaged.
This is what works for me.