A few things I have seen over the years:
Of course your mare should be in top physical condition. If they are already working under saddle and you can develop musculature that way great. They should be braided and show sheened.
apply TONS of fly spray. The worst thing is not being able to stand your mare well because she is flinching and jigging all over b/c of bugs.
Wear appropriate clothing and shoes. Ones you can comfortably run well in.
At mare inspections sometimes you will only present a mare in hand at the walk and then they are allowed to trot free. That is great if your mare is relaxed, but you don’t want her to only be charging around the arena in either trot or canter with her tail in the air…a la Arabian Style. So have her used to trotting free in an arena.
Learn to walk your mare in hand at a good forward walk with her head/ neck stretched to encourage her to use her shoulder and back. You want the walk to look like a panther hunting in the wild…slinky, stretchy and through the back. Not pacing, not clearly four beat and not too sluggish.
When standing your mare have her stand in an “open” position so all four legs are visible. If you can get her to stretch her head/ neck forward a bit to show off a nice front end that is great. But be careful that she doesn’t start to go on her forehand. Also, try to teach her to stand with her hind legs under herself and not parked out, or too far under either. Hold the reins in both hands as shown clearly in the links provided.
When trotting in hand do not restrict the horses movement. Practice and get yourself in shape enough to be able to run full speed with your leading arm held up and open towards the horses head. try to position yourself just in front of the mare’s shoulders. Before coming to a turn on the triangle slow down so you can make the turn!
Make sure your whip handler is skilled in getting the mare to show off her gaits without getting her tense or breaking to the canter. The mare should also be used to a whip handler.
Practice, practice, practice. And if you feel you can’t handle her well then see if you can employ a professional handler at the show. it can be worth the extra $!!
Too much restriction…in all fairness this was her winning trot so the crowd was probably clapping and getting her all tense.
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Larissa-08-11-05_0774.JPG
Good arm position of the handler and you can see how free the mare is to trot.
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Lara-08-11-05_1085.JPG
you can see the runner getting left behind a bit but still allowing free rein for the mare.
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Larissa-08-11-05_0625.JPG
Holding the reins in both hands. You can see his right hand has the reins folded into it and his left hand holding the other rein open.
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Larissa-08-11-05_0628.JPG
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Queen-08-11-05_1156.JPG
Here is a link to my website with some pics of stallions being stood up. They weren’t really trying to get it perfect as it wasn’t a show but I think it gives you good and bad visuals. You can see how a neck can be enhanced like how Hochadel and Rotspon are being stood (although they are a bit too forward, but the best in this group of pics) versus how Bonifatius and Drombusch are standing with their necks up and tense. Comte is being stood up and standing way over his forehand. Obviously these are split seconds in time of my camera but it can show how proper standing can enhance things. Think about how much better you look in a pic when your body is at a 3/4 angle versus straight on!!
http://blumefarm.com/breederscourse2012.html
too much tension on the reins
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Lorelei-08-11-05_1100.JPG
He is holding his hand too low causing tension on the reins
http://www.fohlenboerse.de/fileadmin/galerien/Veranstaltungen%20-%20Termine/2011/Herwart%20von%20der%20Decken%20Schau%203%20August%202011/Lady%20in%20Red%20bis%20Quentchen/Quentchen%20Glück-08-11-05_1214.JPG