Short answer: ask at the moment of delight, make leaving a review a ten-second job, ask every customer rather than the happy few, and never buy or fake a single one. Volume follows consistency, not campaigns.
Timing beats technique. The best moment to ask is when the customer is happiest: the job just passed inspection, the plate just came back empty, the haircut just got a second look in the mirror. An ask a week later competes with a full life; an ask in the moment competes with nothing.
Shorten the path. Every step between "sure" and "posted" loses people. A link texted at checkout, a QR code on the receipt, a card handed over with the keys. Your /add-business listing gives customers one obvious place to say what they think.
Ask everyone. Cherry-picking happy customers reads as exactly what it is, and platforms are good at spotting it. Steady, honest volume, including the occasional lukewarm review, is what makes the great ones believable.
Respond to what arrives. A thank-you on the good ones and a calm, specific reply on the bad ones is marketing most competitors skip. Prospects read responses to complaints more carefully than the complaints themselves.
Never game it. Bought reviews, staff reviews and review swaps eventually surface, and the discovery costs more trust than the reviews earned. The slow way is the only way that compounds. Start by claiming your listing at /add-business, then ask today's happiest customer.