I just sign up for Prime free trials. You can cancel them immediately but still get the full month. I only use Amazon sporadically, though - a half-dozen times a year at most - when I just can't find the thing I need anywhere else for a sensible price.
Just make sure anything you order is either "fulfilled by Amazon" or "Ships from Amazon" and you should avoid that. I personally don't order anything that isn't shipped by Amazon (either through fulfillment or otherwise).
i only shop there when they give us prime for free. sometimes (more frequently the last couple years) it's only a discounted shorter-term trial--so we don't bother, but the last time it was a full month--free. yea, we used it a little. and binged most everything worth watching off video, too.