Cut waste, not winners
Start with the searches that spend without selling — block them as negative keywords. This removes pure waste without touching anything that converts. It is the single safest way to lower spend.
Trim, do not slash
Lower bids on keywords whose conversion rate can't justify them, in steps — not a panic cut. And use dayparting to stop paying full bids when shoppers aren't buying.
Then fund the winners
Reducing total spend often means moving budget, not just removing it: take it from losers and give it to proven winners. AIAdKing does exactly this every night — cutting waste and reallocating to what converts — so spend falls without sales falling with it.