Whenever you can, get a credit card with a rewards program and pay it off in full each month.
Paying the credit card off in full is CRITICAL.
Why use a credit card? You get a billing cycle to actually pay for your purchase and you typically get a % discount. Your credit card usually offers a purchasing portal as well where you can get additional bonus points.
The rewards programs vary, and some are better than others, but the point of this LPT is to use one that gives you some % off.