Spirit, Lemon juice, egg whites, simple syrup, bitters, into your tin. Dry shake (or reverse shake - however you like). Shake with ice. Add seltzer to tin. Strain into glass with ice - I use a larger rocks glass.. Express lemon and drop into drink. Mint as a garnish is nice as well.
Peach Simple Syrup is deadly delicious. I did a 1:1 simple syrup with a single peach sliced up and into the pot. Let it sit for a good 30 minutes.