Good suggestions here...
I love your horse! And the saddle. It looks comfortable. What brand is it if I may ask?
It is a Reinsman Saddle a Comfort Fit Trail Saddle like this Reinsman Trail Saddles - 4136 Comfort Fit Trail Saddle - Safety, Comfort and Performance for rider and horse. I had seen a Reinsman in a local store and just loved the look and feel of it, and had to have one. I had to save a lot, and eventually bought that one on ebay, at a great deal, and it has been everything I hoped for.
But if you're just doing it for fun and not intending to show at higher levels, I'd just use nice quality, CLEAN, tack and let it go at that.
Here's one that's kind of similar to my blouse:
Hobby Horse Clothing Company : Blouses : Roxy Blouse
I have an article in my latest Journal about how to wear a scarf, I'll find it and scan it in to my computer and put it up for you.