If an item is too heavy for First Class and will fit well within one of the Priority Flat Rate mailers it's easy enough to roll the cost of that mailer into the listing or starting price of the item and use Free Shipping.
But there are cases where I pick u a package at work (USPS) and it's a LFRB gut only a pound or two. This is not a benefit for you or your buyer. It would have cost less Postage if shipped Priority in a plain brown box.
As a new seller you need a few things.
#1 always is a good postage scale and a set of calibration weights to check it with from time to time. Both can be gotten here on eBay.
#2 is a zone chart for your "ships from" zip code, this can be pulled up and printed at: https://postcalc.usps.com/DomesticZoneChart
#3 a good working knowledge of what is available in terms of shipping methods.
1. First Class covers items under 13 ounces if buying postage at the Post Office window, 15.9 ounces if you print your own postage on-line.
2. Media Mail, know what is and is not allowed.
3. Retail ground/Parcel Select is not a money saver unless the item is over 1 cubic foot and/or heavy. But there are items that can not go via air, know what these are.
4. PRIORITY, This has the most variety and therefore most confusion. Zoned you will need that chart at #2 remember to consider dimensional weight for packages over 1 cubic foot. Flat Rate, this requires the use of the provided and marked Flat Rate Mailers. Regional Rate also requires specially marked boxes, RR'A' ships at the 2# rate (max 15#) and RR'B' ships at around the #5 rate (max 20#). Cubic Foot pricing is complicated. You will need to do some measuring. It goes in increments UP TO BUT NOT OVER .01, .02, .03, .04, .05 cubic foot, and maxes out at 20# . What is good with the Cu/Ft pricing is that you can use any non Flat Rate or Reg Rate box or your own plain brown boxes. here is the chart
Sorry about that. My internet is running so slow today. I was bidding on something and had to get back to it and as soon as the picture came up I grabbed the cut and paste.
