I adjusted it on land once (took me a good 2 hours) and never touched it since. Burning the ends is mandatory. It was great in the water right away and I have had no reason to mess with it.
I keep it simple with a knife sheath on the left waist band, torch on the left chest D ring with a bungee retainer, and the pony clipped into the right chest and waist D rings. I've added another bungee loop to the left chest D ring to keep the inflator tidy.
Make sure the crotch strap meets the waist strap without pulling it down, so leave enough length to go around the waist strap when you are holding the waist strap horizontal.
Also, use some tight inner tubing or whatever to retain the doubled up ends coming out of the buckle and crotch strap. Keeps everything neat and tidy.
When I started out I had a bunch of accessories dangling off my hip D rings or even stowed in the storage pack my bp came with, but I've since added on a pocket to my right thigh which keeps my DSMB, spare mask and storm whistle.
The only issue I had is that Scubapro's pull out weight pockets that are supposed to go on the waist bands are so long that I could not actually use them (I am too skinny for them by a good margin, so not enough webbing to have them on left and right, total design failure in my mind), so I ditched those and added small cam band trim pockets to my waist strap instead to carry weights. With the pony, I use 1 trim pocket each on the left cam band and waist band, with the steel pony providing the same amount of negative buoyancy on the right hand side. Without the pony I'd add the mirroring pockets on the right side also. I can just about slide the pockets on over all the hardware without having to undo the metal bits, so that's a quick enough adjustment.
A somewhat related tweak was that I had to move my top cam band down one slot in the STA (luckily it has that option) and invert my DIN reg by swapping hose ports so that the protruding part points down, otherwise the first stage would hit the back of my head right away.