I've been hearing a lot of chatter on the streets lately about sellers wanting to know how they can make their business plummet. I'm not talking about a little fall. I'm talking about a 1 mile wide meteor smashing into the Earth. A flameout to be remembered for eons. Well, dear friends, I've been thinking much about this subject. After maybe, say, 5 minutes of thinking about it, I'm now qualified to tell you everything you can do to make your humble shop be a failure of wonderful magnitude.
1. Threaten your buyers with the fact you have their address
This is the first step you should take. You need to let your customers know you are not to be messed with. To that length, be sure to mention that you have their home addresses if they buy from you. YOU KNOW WHERE THEY LIVE AND YOU CAN FIND THEM. Be sure to sprinkle this liberally everywhere. Right in your announcement. In your policies. Hell, even in your profile. You are not a seller to be messed with. Say you're doing it to prevent negative feedback or make sure you get your money. Actually, you don't need a reason. You just need to let your customer know you're not one to be pushed around.
2. Leave negative feedback the second you are aware of purchase from shop
Look, this is a preventative measure. Many of us live in the blessed US of A. We believe in preemptive strikes. You should have plenty of reasons for leaving negative feedback. Either they didn't pay enough for your hard work. Maybe they didn't pay quick enough. Maybe they should have bought it yesterday instead of today. Their Etsy and PayPal shipping addresses are off. They asked you a question in the note to seller. They made you do 5 extra minutes of work you would rather not do. They were probably going to send you a convo later on whining about something. These are all elements that add to you having a negative experience on Etsy. At that rate, they deserve your negative feedback. Hell, you might not have liked their name. It's your right as an American to stand up for what you believe.
3. Make sure to let everyone know that you have a DNBF list, and make no bones about who is on it
This one is a no-brainer. You need to go find people you do not want to buy from (forums are a great place to make snap judgments about people and hold your money over their head) and then go post that list on your shop. To do this best, make sure it's the first thing in your announcement. Also, extra credit for putting the list in your listings. Even more credit if you name your pieces with cute slings against sellers you don't like (ie SellerX Is A Bigot Who Makes Necklaces That Suck Compared To Mine). The more ad hominem attacks, the better.
4. Tell everyone you are a smoker with 50 cats
Look, who cares about those crybabies who go "Wah, I'm allergic to smoke and cats". God (which we will come back to later) made these people weak, and we shouldn't cater to them. Tell people not only do you smoke 2 packs a day, you rub ash in your knittings and rub them all over your cats. If these people have a problem with it, just tell them they shouldn't be such wussies and take a Benadryl. We as a people have catered to these whiners with allergies too long. I'm allergic to pine pollen, but do I cry and whine at the trees? Do I make sure everything I buy has to come from somewhere without pine trees? No. And neither should they. Stand up for your rights!
5. Put your religious leanings everywhere around your shop, and make them as extreme as possible
It is your duty as a good Christian/Muslim/Jew/Shinto/Etc to let everyone know what they believe is wrong, and you are right. All of your customers are sinners, and you are their path to salvation. If they don't repent, they cannot buy from you. Make lots of references to the Rapture, or Jihad, or something will alienate lots of people. If they disagree with you, well, it's no big loss. They're going to the lake of fire anyways.
6. Make sure you ship your items as badly as possible
So, finally, someone ignored all of the previous warning signs. They still bought from you. How can you make sure they will never do that again? Easy. Make sure they're flamingly pissed off when they get the package. Some great ideas abound. Include used kitty litter as a protective material. Put in exploding dye packets for a fun surprise. Put "please handle roughly" on the envelope or box. Use the flimsiest packing material you can (duct tape two pieces of copy paper). Put in lots of ambiguous white powder with skull and crossbones signs. Hell, don't even ship it. Also, take your time shipping it. Make sure your customers know this too. It's your life. If you don't want to go to the post office for 2 months, so be it.
There you have it. With these 6 easy steps, you can pretty much ensure no one will buy from you ever. Now, you can leave your Etsy shop with no regrets and focus on something that truly matters to you.