When dressed to the nines

Well, I listed several things, but if I had to choose just ONE factor, it would be well-groomed hair.
If my hair is greasy / limp / in a mess / in whatever condition that makes me feel kind of miserable, even elegant clothes and perfect makeup will not be of much help. On the contrary, if my hair looks great, I will feel and look beautiful even in a simple casual outfit and with little or no makeup.

That's good logic, Cat! And makes perfect sense...

What a great topic! Mine would be coaxing my hair into a curly mane, a well-fitted black pencil skirt, and the right pair of stiletto pumps.

Ohhh... sounds amazing La Belle!

Definitely a fresh haircut - a pixie that is just sharp. Wearing a skirt or dress that swishes around my legs when I walk. Wearing clothes that feel good to the touch, so you just want to pet them all the time...

Agreed, Astrid! I'm with you on the pixie, and I am also very tactile.

Right - tactile was the word I was looking for. Something can make me look good, if it feels horrible to the touch I'm not buying it.

Hair, definitely. I'll also add -- lipstick. Some color on my lips goes a long way, especially as I'm aging.... and fading. It can be as simple as a tinted lipgloss. Just to add a bit of color.

Also just feeling comfortable in my clothes, nothing pinching or binding or making me feel fat. Clothes that fit, regardless of what my size is. This includes my shoes -- well fitting shoes that don't hurt. I never feel beautiful if my feet are aching and full of blisters.

Having my nails painted. It puts a smile on my face. Makes me feel pampered and cared for. I never thought I'd say that, as I went for decades without ever painting my nails, and didn't start getting regular mani-pedi's until about 3 years ago.

Wearing my contacts instead of my glasses. I feel ugly in my glasses, and like there is a window between me and the world. (Sunglasses not included -- I love sunglasses).

Taking a long walk and having pink in my cheeks.

For me: wearing a black top, ideally with some contrast in it. And having a deep enough colour on my lips (and my eyebrows of course). Hmm, I am sensing a theme here. And the very best, rosy cheeks because I've just come in from a walk.

Discovered during my university days: being "kissed by the sun" across the bridge of my nose and cheeks (I used to replicate that effect with blush). And wearing the right colours: This was before "Colour Me Beautiful" and me realizing I am a Winter, but I was shocked to notice that I looked and felt better in faded blue jeans and an old cut up white sweatshirt than I did in my dress-up dating clothes (which were all in Earth tones, this was the 70s).

L'Abelle, isn't it interesting how often the things that feel good end up looking better than what we think should look good? I really like your list!