Weather
If you don't go out climbing in the UK on marginal weather forecast days you'll probably never climb. Fortunately, there are other climbing areas around the world where the weather is less fickle. It is nonetheless worth taking note of the weather forecast, particularly if you're off on a long adventure. Also, do a bit of reading up on your intended climb and make sure you can get to the crag and get off it so that you can make it to the bar before closing time.
If you don't climb in the UK on marginal weather forecast days you will probably never climb!
Clothing
Climbing clothing must allow the wearer unrestricted movement, however contorted a position you may find yourself in. How much warmth it needs to provide depends on the time of year and destination, but it's usually a good idea to carry in something windproof / water repellent for wearing at the top or for belaying, and perhaps for evacuating the route if the weather closes in...
Provisions
Pack food and drink sufficient for a day out doing strenuous exercise - at least 1.5 litres of fluid per person per day is required - more if you're in a hot place.
Warm up
If you're off to climb something short and technically difficult, consider warming up before you get to the crag. At the very least do so at the foot of the route or climb a couple of very easy routes first. You'll not perform to your max until you are properly warmed up. Sometimes the approach walk is good warming up exercise but if it's short, consider jogging to the climb instead.
For others, getting psyched for a climb might mean stomping around at the foot of the route building up some aggression and power
Stretching
Along with a general body warm up, stretching exercises are essential. Injuries are more likely to occur on cold or unstretched muscles, particularly if you're cranking on tiny crimps straight away. If you have old and nagging injuries but still need to climb, get them sorted out. Tape any strained finger tendons to reduce pain and further suffering, and strap up any weak muscles or knees.
Psyching for the climb
It isn't appropriate for everyone, but some climbers use a form of relaxation technique, such as yoga or meditation to help focus their minds. You do need to have some knowledge of these techniques and be properly trained before you can expect to reap the benefits. For others, getting psyched for a climb might mean stomping around at the foot of the route building up some aggression and power, or perhaps quietly contemplating the route from below and from all angles, or becoming absorbed in sorting gear.
Look ahead
Survey the line you are intending to climb and try to work out the moves from the ground. Suss out the most likely looking places for good gear placements and where you might find a rest for weary arms.
Regardless of what your partner says, always add in your favourite talisman piece - you'll only blame failure on not having it with you!
Use a system
When you sort out your gear, make sure that it is racked systematically and to your preference. That way you'll always know where to find it even if you can't take your eyes of the rock to look for it. Regardless of what your partner says, always add in your favourite talisman piece - you'll only blame failure on not having it with you!
Individual differences
Preparation for a climb is all about being at ease with what you are about to do. It is a combination of lots of elements, each of which will vary from person to person so don't necessarily expect that something that works for your mate will work for you. Even the moves on a climb are done differently by different climbers - depending on their height, reach, strength and levels of motivation. Be sure you are ready when it's your time.