Usually the buyer pays for all shipping and handling costs, but if you have ever shipped an item before, you know that there are many costs associated with shipping an item.  You have to pay for boxes, tape, bubble wrap, stuffing, and all kinds of other materials needed to ship an item properly.  Here are some tips that I have learned over the years that will help you save money and ship items properly. 

• Make sure that fragile items are packed securely.  There are cheap ways to do this, but the point to be made is that you MUST use bubble wrap, and you MUST pack the box tight with styrofoam peanuts, newspaper, or other padding material.
• Make sure that sensitive items and clothing items are water proof.  It is definitely possible that your item could get wet during the shipping process.  You don’t want pen marks bleeding through onto a pair of khaki pants.  My suggestion is to put items in zip lock bags or cover them with styrofoam padding material. 
• Don’t inflate your shipping price.  I know that plenty of sellers do this on Ebay, and I Know that is your decision to buy an ipod for $100.00 with $50.00 shipping.
• Buy a paper shredder.  I did this and it has helped tremendously with recycling my old magazines and newspapers to make perfect packing material that keep your item packed securely in the box or mailer.
• Buy bubble wrap in bulk.  You can find large amounts of bubble wrap at a very cheap price.  It is much cheaper to buy this way than buying it at walmart or other postal supplies stores.  Do this only if you ship mostly fragile items.  Otherwise, it might not be worth it to you. 
• Use USPS Priority Mail.  This has been very convenient for me.  If you ship mostly smaller items such as clothing, consumer electronics/accessories, or cell phones/accessories, then priority mail is the way to go.  Most of the time you can ship something of this size around the U.S. for about $8.00, but it is received in about 2 -3 days on average.  The buyer does not mind paying this much for shipping if they know that they will receive it quickly.  And the best part is that USPS provides FREE boxes and FREE tape if you tape it up at the post office and FREE labels.  You know that I LOVE THE WORD FREE!  It is a very convenient and very efficient way of shipping smaller items that do no require a great deal of care.
• Make sure international buyers email you before they send you money.  You may quote a flat shipping fee for the U.S., but if you are shipping to China, the rate is much different.  Make sure they email you beforehand in order for you to give them a shipping quote. 

These are a few tips that I learned.  When I first started selling on Ebay, I got burned many times by losing money on shipping costs.  Try these suggestions to help keep your shipping costs down.