Below, notice how kerning reduces the large gaps between certain letter pairs, making them consistent with the rest of the font.
Always use kerning. If you use paragraph and character styles, turn on kerning as part of your style definitions.
text-rendering: optimizeLegibility, and enable the OpenType feature
Professional page-layout programs make it possible to manually kern letter pairs. For professional typographers, this is a mandatory skill, but for everyone else, the built-in kerning is adequate.
One of those programs, Adobe InDesign, has a feature loathed by every type designer in the galaxy: the “optical” kerning option, found in the formatting toolbar. When you activate optical kerning, InDesign ignores the kerning that’s in the font and applies a spacing algorithm to the letters. This is akin to putting your fine cashmere sweater in the washing machine. Don’t be fooled by the benign name—it will mangle your font. Always use the “metrics” option.