I've worn spurs or carried a dressage whip in the past, with other horses. When I was a kid riding western and bareback, we slapped our reins against the horse's shoulder or butt to get them to go. Dressage is a bit more refined than the riding I did back then. The dressage whip operates more like an extension of your arm -- a little tap here or there to help the horse understand where or what to move. The spurs used in dressage are short, blunt stubby things -- a far cry from the fancy rolly jingle jangle ones worn by cowboys and cowgirls. With all of my previous horses, I've carried a whip and have not worn spurs. The exception was Auke, my Friesian. I used both, at the same time, to keep him going. He was a big, black, beautiful slug.
In general, I have avoided spurs because I didn't want to inadvertantly poke the horse. My feet tend to do the airplane thing -- toes pointing out and my heel (and the spur) pointing in. The position of my leg has improved over the years but I still worried. And, I certainly didn't want to poke my extremely sensitive mare. She would have a lot to say about that and I'm sure it wouldn't be pleasant.
When I first bought Lucy, I needed neither. She's naturally forward and with eight months of full time training with Sandy, she was very responsive. She still is, most of the time. The only exception, is when she is in heat. Then she's sluggish and grumpy and resistant. A few months ago, I started carrying a whip when she was in heat. I think I tapped her lightly once. In general, though, I never had to use it. She knew I was carrying it and that was enough.
I've always thought that I have quiet hands. Quiet enough for Jackson or even Winston. But, as I learned at Sandy's workshop a few weeks ago, not quiet enough for Lucy. I've been working on eliminating any "noise" -- fidgeting, adjusting, crossing my hands over the withers. The thing is, when I carry a whip it is hard for me to get everything coordinated AND quiet. I have much steadier contact with the reins if there isn't a whip in my hand.
Sunday morning, I pulled out my spurs and slipped them onto my boots. I swung onto Lucy's back being verrrrry careful not to poke her. I made sure that my toes and heels were correct and we walked off. Lucy was in a sleepy, mellow mood and not very responsive to my leg. She ambled more than she walked. I gave a squeeze with my upper calf -- the response was so small that it hardly registered. I turned my heel towards her and gave a very gentle nudge. She flew forward in a big trot. ...and we continued on to have an excellent ride. I never used the spur again; I didn't need it.