I have a tb mare with a little irish in her. I have shown her in best turned out very successfully in small shows.
What colour is she/ he because ours is a dark bay and we were told to wear a hacking jacket rather than a black/ navy jacket to make the horse stand out more. Also use a coloured browband except if you enter hunter classes. Plus, if you can sew the plaits rather than use bands as we were put down to 2nd place instead of 1st place for doing this. Also, i would suggest showing in hack/ riding horse class depending on size of horse
1st is of me and came 1st in this class
2nd is of me on my old 4 year old irish sport horse gelding in a riding club horse class with my other tb mare ridden by my sister. I came 2nd, would have come 1st but cantered on the wrong lead on one rein. My sister didn't do too well as the mare tends to get excited when there is a group canter :P