Some folks on twitter asked me for tips on dismount/remount. I'm not a National Champion. Therefore I cannot garuntee that my summary of how to get on and off a cross bike is the best way. Helen Wyman or Ian Field or Paul Oldham would probably be a better person to give the best best advice. So this is NOT advice, this is the way I learnt to dismount a cyclo cross bike for a cyclo cross race. This is my way, broken down simply.
Note: Somewhere Andy Waterman has a video of me smashing into a hurdle.

Dismounts
Practice flat-out dismounts to clear a hurdle quickly. I go to the park and do this over and over again.
When I first started I didn't put an obstacle in the way, I just decided I would dismount when I was level with a tree.

- approach with hands on the brake hoods
- unclip your right foot.
- swing you leg over (practise swinging your leg really high, lean on your hands to retain balance)
- grab your top tube with your right hand, put your weight on this arm. Left hand stays on the hoods
- as your righ leg swings through, use this as leverage to twist your left foot out.
- I set my right foot downbehind my left.
- I place my left foot down as a large step to maintain speed
- the next stride will be with my right leg and it will power me over the hurdle
- i pick my bike up at a tilt / flicked out. This allows me to lift it lower (less effort).
- do not lift your bike from under the top tube, your wrist is flimsy. your weaker and your lifting it too high that way. Always lift from on top of the top tube.

Notes
Speed on the approach gets better with confidence. It takes skill and nerve. It takes patience to develop skill and nerve.
I used to play football for years, I'm used to smashing into people and skidding along the ground. As adults we grow more fearful as we know it will hurt, children have no experience of pain and thus are more ready to just start whalloping into barriers.

Look ahead not down. You'll get tangled up in your feet if your looking down at them.

Don't be delicate with unclipping or lifting. My bike is a solid thing. I use standard Shimano M520 pedals, none of this carbon nonsense. They are dependable and metal and can take a smashing as can my alloy frame.
Tell your bike your the boss and leap off it and tell them pedals your feet are coming out of them. 

On the dismount, you can bring your right foot through and infront of the left foot. Ben Spurrier does it this way. But it doesn't feel right to me. Practise will help determine which is right

Don't come to a complete stop. Do not brake at the last minute.

Remounting after running section (e.g flat hurdles)
- move your right hand back to the hoods or top of bars
- Simon Burney's cross book says - avoid dropping your bike too hard, just in case it bounces out of control
- I move my hips inline with the saddle
- I leap with my left le. I'm not going super high, I'm trying to travel up and across
- my right leg moves into a little tuck to clear the back of the bike

- you need a leap of faith, you won't miss the saddle. Try to land on the inside of your thigh on the saddle as you pedal away shift back onto your butt.
- i look down intially just to spot my bike but then look up and ahead as I leap on 
- as your right leg swings round, I feel it gives me more momentum to hop on. It pulls my body over and onto the saddle.

Notes
If you double skip, its no problem, its just slower. Just keep trying and getting your head around doing one jump.
If you skip, then your second jump is actually lower and less powerful than the first. So if you can get on doing that, then you can get on doing just one jump
It takes me now 2 steps to remount, I just started slowly and practise until it became second nature
Make a little loop 50m with turns either end in the park and just go round unclipping when your on the striahgt and try remounting before you take the corner.
I flick my bike outwards, make sure it is put down vertically as it could veer off.
Wwatch you tube clips, watch other races, watch the elite jump the hurdles.

The video below is one of me 3 years ago. I'd be doing cyclo cross in the local leagues and this was my first National Trophy. My approach and unclip is alot smoother. I just didn't pick my bike up.
On the remount I didn't launch myself into the air, my first jump with the left leg is quite weak.
I am the rider in blue.


Examples of what I trying to say.

Keeping the bike low on the hurdles

Greg Simcock - tilted the bike. He is driving his right leg over the hurdle. Look how the bike is quite low.

The rider in grey is lifting his bike too high. This might be because he's down the slope. Look how the elbow is nearly above his head.

The VCL rider should now just push with his left and hop on. The rider in grey kit should now extend his arms and move the bike forward. He has dismounted on the wrong side, the course is on a camber, he will now have to work against the camber and up hill, he will also have to jump alot higher than the other rider.