Throughout the day I appear more or less passing depending on the setting, I find I look best in bright dept store lighting. My part asian skin is GLOWING freakishly I think it's one of my best gender markers.
The first and strongest impression that I'm looking female is upon waking and looking in the mirror. Somebody here also mentioned this and I can relate. Wow! (Just be careful not to stare because you start to pick out flaws and the dysphoria which will peak at the end-of-the-day only returns - faster)
Then there's the dept stores. I don't know about you gals, I've read that many hate the lighting (I do in 3 way fitting room mirrors however

) but seeing myself in the makup section column mirrors I feel I look my best. I am wearing no makeup, and I get the sought after, "hi mam" from the makeup gals. Talk about your heart FLuTterING in giddiness. Oh hi, just passing through!
So when and where do you feel you are at your most feminine appearance? Bathroom vanity lighting? In the car? Outside daylight? Evening at a bar or nightclub? Sitting under the table?