I’ve been trying different packaging methods and here is what has worked so far. It is overly complicated right now, but I feel weird giving someone a huge t-shirt bag for a 3″ painting.
Small items like stickers, etc: clear or colored plastic party favor bags / also I have paper lunch bags handy if they are a gift. Slap a label on the front and stick a business card inside and good to go!
Under 6 inches wide, purchase $5 – 10 and up: I have little paper bags with handles, can hold multiple 4 x 6 prints or small framed paintings. Looks really nice. You can buy in small – large bulk quantities multiple places (Michaels, Dollar tree, online)
Larger than 6 inches, under 14: I wrap them in clear small trash / kitchen plastic trash bin bags with no scent or string (they sell these at Costco) – I then might still stash these in a clear t-shirt bag, it just depends.
14 inches and up: clear t-shirt bags from Uline
I haven’t sold any larger than 18 x 24 yet except as commissions.
>> Tip: have a container designated for bags, and stash a set of smaller bags behind a rack / area where you have the smaller items on display.