I try to save sturdy boxes that are larger in size for sending packages each year. I also save "filler" type material from each time I receive something I've ordered - peanuts, brown paper, the air bag filled kind, etc. and keep it all in up to two large black trash bags upstairs in a storage area.
I always reinforce the bottoms and sides of boxes I use with extra packing tape!!!
To make the boxes prettier I cut pieces of Christmas themed stationary to size and write return address and address of recipient on that before applying to box so that each label is completely covered with packing tape.
I've always wanted to "line" the inside of the boxes with pretty wrapping paper but haven't taken the time as of yet.
Instead of trying to send gift baskets I am going to try doing gift boxes instead. I've seen really cute flat style boxes - with lids - that you can line with pretty paper and then fill with themed items. So this year I am shipping a couple movie night boxes and a couple of baking boxes - I'll fiddle with the contents so they all lie flat and fit snug into the boxes - maybe using colored tissue to fill in gaps.
I also can share a couple of thoughts on shipping cookies - I've found that wrapping 2-3 cookies in bundles - tightly wrapped in plastic wrap works well. The layers of plastic wrap - I do two - help to cushion the cookies and keep them fresher. I just write the type of cookie on peel and stick Christmas gift tags and put one on each bundle. Then I fill the tin or box with bundles adding extra tissue to fill in any gaps so all is very snug. I also put a flour tortilla shell in the bottom of each tin to help keep cookies soft.
Then when I package the cookie container in a larger box of presents to be shipped I try to make sure it is completely surrounded with packing material - not right up against the side of the box or against other things.
Lastly, we invested in a folding cart that collapses - you press and lever and swing up one piece that you can push a little flat bed with - this is a real life saver when taking several large packages into the post office from my car!