Anyone that wants to accept checks and credit cards really should look into www.propay.com
I use ProPay for all of my CCs. I love the easy to use swiper that they have, and it has definitely increased my sales.
I've also used it a couple times for an e-check. Basically, you use the web interface to enter the check info, and then the customer voids that check. You find out if it will pass or not within the first three minutes.
After one show a couple years ago, I refuse to take checks ever again. I sold an outfit to this woman for about $225, and then she found a $120 necklace that matched perfectly and bought that one. $345 that I am out. I checked her address, her license, etc, too. Everything looked like it matched so I allowed it. Boy, was that a mistake!
Now that I have ProPay, I will never allow personal checks again unless I KNOW the person in question. Interestingly enough, I've never had a customer get mad because I could not accept checks any more, and they were usually very sympathetic when they knew why.
Where to start? I sell mostly at fair type things, and a little bit online.
For stuff that is purchased via my Etsy shop, I usually will figure out the size of an appropriate mailer, and then pack the snot out of it - even though my stuff is strong enough to take some abuse. For example, if someone buys a necklace, I would wrap it in paper towels and then seal that in some sort of plastic before sending the item in a Priority Mail envelope.
I'm a firm believer of not giving the customer any reason to hate my stuff, if I can avoid it. There are always going to be some people that are not happy, but you can work to avoid it.
The best thing you can do to help yourself would be to make a sample of your items, package as you see fit, and then bounce the package around a bit. Yes, this does mean that you will be taking a chance of breaking something. But if you do so, you will be able to see what the stress points on your items are, and go from there. I did this for each of my breakable items and was able to figure out some pretty decent packaging.
Like the others said, make sure you always include your information in there, too. I like to include a quick note and (if they make a large enough purchase) some sort of small "free with purchase" to thank them.
I've been fiddling with my own stuff for ages and can answer: yes, you are considered self employed if you sell on Etsy. You may only be making a tiny amount, relative to your 'day job' but it still counts.
The IRS will want its cut, of course. So far, it's about 1/3 of your profit. I suggest getting a decent, small bookkeeping system to track stuff - I've had really great luck with WorkingPoint (www.workingpoint.com) for setting up and keeping simple books. It's free and can grow with you until you decide if you need something bigger.
Your state may or may not have different ideas about what you need to do. In Texas, where I am, you do not need a business license to sell your crafts, but you will be nailed to the wall if you do not properly report, collect, and submit State Sales Taxes. In fact, at shows that I go to, one of the first things that they check at the door is your license - and they may spot check it onsite too.
I suggest that you do a quick google search on your own home city and state, like "Houston Business License" and then give the appropriate authorities a call. Believe it or not, the authorities are usually very friendly and helpful.
I often sell at conventions. At one, a couple years ago, I had a person come up to me and ask who my suppliers were. I asked why and he replied that he thought that it would be great to start making and selling the EXACT same stuff I was.
I ended up sicc'ing the husband on him because that was beyond wrong.
I know that it's late to post, but after reading this, I wanted to mention the ultimate place to get some very odd stuff: Home Depot.
According to my friends, I could open a small bead shop of my own with all the bits and part's I've accumulated. In order to organize the stuff, I went to Home Depot and picked up a bunch of the stacking plastic containers that have a whole bunch of little drawers in them. It makes creation easy - just grab the drawer and go. I can lay out the drawers on my workbench, make what I want to make, and then put them back. Best of all, they are interchangable, for the most part, so if you find that some things are more commonly used, you can just keep them on a shelf near you.
Home Depot also has other things that Jewelry makers may like: Welding rods, soldering irons and solder, flashing in aluminum and copper colors, different kinds of organizers/toolboxes for things, pegboard on the cheap, etc. Personally, I'm always shocked that more jewelry makers are willing to pay huge amounts for what is essentially the same thing - but without the construction coloring.