Dont get dependent on having the rack on your right side (or your left). Learn
to be ambidexterous. Sometimes the climb dictates how you wear the rack.
Practice switching leads and gear quickly; learn good rope management skills.
When the thunderstorm and darkness are approaching, it helps to be efficient.
Unfortunately, most guide books are made too large these days to conveniently
carry. For longer routes, make copies of the descriptions and carry those
instead.
On shorter climbs, clip your descent shoes and water bottle to the back of your
harness so you dont have to deal with a pack.
Time was, you could leave your gear lying out unattended at the bottom of a
climb and it would be there when you got back. No longer, if you want to keep
it, stash your pack out of sight.
If you want to be a real trad, learn to second with a pack. If you want to be an
alpine climber, learn to lead with a pack. Hauling is not always a viable
option.
Carry a small pocket knife for cutting away old manky slings and making lunch.
Dont cop an attitude nobody is that good. Assholes who are legends in their own
minds are the ones that give all climbers a bad rap and get areas closed. A
little courtesy goes a long ways.
Have fun and climb smart!!