Tip #3 - Movements
Think of the test movements like the structure of the book. Ride them with a beginning, a middle and an end!
Every movement has a beginning a middle and an end. The judges want to see the quality of the movement in all its stages to give the top marks.
Lets use the lengthened trot as an example. A great lengthened trot begins in the corner where we set our horse up, get the hind leg under and ready to take the weight behind whilst simultaneously lifting the shoulder (see tip #2 for more on corners). As you straighten the horse across the diagonal, the frame is slightly lengthened by the rider by lowering the hands slightly and allowing with the hand forward, inviting the horse to lengthen his body. A horse can only extend his hind leg forward if his shoulder is up and the neck and frame is lengthened, and he can only extend the trot as far as he can bring the hind leg under his body. Hence the lengthening of of the frame and a correctly ridden corner is critical for a quality lengthened trot.
So now our horse is in the position and balance he needs to extend the trot like a gravity defying deer across the diagonal leaving the judge starry eyed and jaw dropped on the floor! But we're not finished yet! We have to walk the tightrope of asking for as much lengthening as we can without our horse losing his balance and falling into a hot mess on the forehand.
Now we have have to finish the movement in order to get that top mark! The rider half halts with the seat indicating to the horse that we want to rebalance him and redirect all that energy back into a working trot. If we have played our cards right our horse is still balanced with an uphill shoulder and he just seamlessly pops back a few gears into a beautiful trot and we then ride into our magical corner and use it to re-balance him and get the hind leg back under and him listening to our seat again.
And there we have it, a beginning, and middle and an end! At every point the judge can give you the maximum marks. If at any point during the movement the horse becomes unbalanced, runs and falls onto the forehand they have to take marks away. It doesn't matter how amazing the lengthening was if the transition back to working trot was on the forehand and unbalanced, the judge has to take away marks.
So it's so important to only ask for as much as you can safely get back in any of the movements. Like an gymnast, no matter how incredible your triple back flip is, if you don't nail the landing you won't get the marks. The same is true with your dressage movements.