Deadhead for longer bloom, best done while wearing tie-dyes. Remove flowers after they have bloomed. This prevents pollinated flowers from making fruit or setting seeds, which causes the plant to senesce, or get old and stop making new flowers. And while you're in the removing mood, pinch back the tops of coleus, and of fall-blooming perennials like chrysanthemums, asters, and helianthus (I'm trying this on my Jerusalem artichoke sunflowers this year) to promote branching and make more flowers happen later in the season.
Side dress. Stuff that has been growing since early spring can benefit now from a "side dressing" of a line of dry fertilizer, like 5-10-5 or 3-4-4, scratched lightly into the soil alongside rows or individual plants. Keep the lines several inches away from stems. Water well afterward. Avoid using dry fertilizers on hot dry days unless you water well before and after applying, as many are salty and can burn. Organic fertilizers derived from compost, manures, or seaweed are usually more gentle to plants and release more slowly; gentlest and most effective is fresh worm compost, because it slowly breaks down and releases nutrients.
Clean up your act. This is turning out to be a very productive year for ticks, so if you find yourself in a high-traffic area (especially the woods and almost-woods), keep a lint-roller near the door. Roll it over your pant legs to pick up unwanted visitors and traveling seeds. Peel off tape and dispose carefully (I bag mine). NOTE: Handpicking is still recommended for your hair.