Don't Pay Shipping Costs

Most online stores don't charge shipping if you spend over a certain amount. Amazon encourages you to buy into their Prime program which currently costs $99 a year and offers free shipping and access to videos (many of which aren't free) and I have never found this is worth the cost.
Note:You can sign up for a 30 day free trial

I now buy a lot of items at Amazon that I have trouble finding elsewhere (my favorite hair color is one) so I keep a list of items that I want to purchase on Amazon but are not in a hurry for. When something comes up that I want to purchase immediately (Amazon prices are often the cheapest), I combine everything on my list to total over $35 and purchase everything at once.

You can do this for any number of stores as many of them sell regular household items.