To secure personal loans at the best interest rates, maintain a good credit score and history, compare lenders, negotiate terms, increase down payment, choose the right loan type, consider a co-applicant, opt for shorter loan terms, and showcase stable income. It's important to shop around for loan offers and read the fine print before committing. A co-applicant with a better credit history can help secure lower interest rates, and shorter loan terms often result in lower overall interest costs.