Pat salmon dry, and sprinkle both sides evenly with salt and pepper.
Heat 1 tablespoon oil in a large nonstick or cast-iron skillet over medium-high until shimmering. Add 2 salmon fillets, skin side up; cook, undisturbed, until golden brown, about 2 minutes. Flip salmon, and cook until an instant-read thermometer inserted into thickest portion of fillets registers 110°F to 115°F, 1 to 2 minutes more. Transfer salmon to a serving platter. Wipe skillet clean, and repeat process with remaining 1 tablespoon oil and 2 salmon fillets.
Remove skillet from heat; add wine and lemon juice. Return skillet to heat over medium-high; cook, scraping up any browned bits from bottom of skillet, until liquid is reduced to about 2 tablespoons, about 2 minutes. Remove from heat. Add butter, and swirl until melted, about 1 minute; add capers (if using) and herbs. Pour sauce over salmon.
