The dimensions and weight of a package should be your primary consideration when choosing a shipping method for your items. Consider buying a shipping scale instead of using a regular scale like bathroom scales since they are not accurate for weighing packages. Use the lightest packing material for your packages, bubble wrap and packing peanuts are the best choice. Newsprint or old newspaper adds additional weight and charges, so use them sparingly.
Go online to have an idea of how much you will be paying for the package. There are some shipping companies that have calculators on their websites. You can also determine the shipping rate using destination zip codes. Try comparing Parcel Post versus Priority Mail as well. Sometimes sending via Priority Mail is cheaper.
Get familiar with possible restrictions when shipping items internationally to avoid unwanted costs due to returns. There are certain countries that restrict certain items in their country. There should also be necessary Customs documents declaring the value and content of the package. Review if your item qualifies for special shipping rates which can save you a lot of money.
Compare prices, depending on your requirement like delivery time or low cost, one or the other is probably a good choice. Set a number of days on your shipping terms to lessen your number of trips to the shipping or post office as possible. When traveling to the post office, ship as many orders as you can. This will save you time and money. You can also order free shipping boxes to save you a few dollars for packing materials.
If you are using a drop shipper, have a prior agreement that they will shoulder the shipping cost in case the package is return for a refund or if the item is defective or damaged due to shipping.
Always remember to pack and ship your items the way you want them to be packed and shipped for you. Always do it in way that it will not cost you more money due to returns and damage, aside from receiving a negative customer feedback due to shipping issues.