1) Should your vector design be rejected, ASSUME THAT YOU MADE A MISTAKE. Any of my designs that were rejected by Spreadshirt were rejected due to my own errors. You may think nothing is wrong with your design (don’t get so attached to its ‘brilliance’ that you lose perspective), but there IS. There have been a few times where I was POSITIVE everything was tip-top in a design only to discover –oops!—I made a mistake.
The Spreadshirt team WANTS you to be successful and make money. Your success is Spreadshirt’s success. Look at it this way: The standards imposed by Spreadshirt will help the quality of your work and thus increase your chances of financial success. The team is reviewing probably hundreds if not thousands of designs daily. Assume that they know of what they speak, because they do.
2) Sales will not occur the minute you post your design or unveil your shop. Patience, mates. It takes time (and mistakes) to build anything worthwhile. Some tips:
The Marketplace: Use proper tags for your designs released in the marketplace. DON’T try to throw in hundreds of irrelevant tags hoping for a bite. Make certain your tags actually are relevant to the design being depicted. It allows your work to be found easier for those actually looking for that particular style/design.
Your Shops: Whether a premium or basic shop, the fact is this: You can have the greatest designs in the world, but what difference does it make if nobody is aware of them? Promote. Don’t waste time trying to cover every base of every market. Focus on targeting those individuals, blogs, sites, etc. that actually represent the style or type of designs/motifs your selling. The goal is to get SALES not simply hits. If you invite a bunch of Mormons to purchase your atheist designs…well…
3) Mistakes will be made across the board. Don’t let them get you down; learn from them. This sounds stupidly simple, but sometimes frustration over mistakes can threaten to destroy your motivation and cause you to lose sight of your goals (you have set goals, yes?). I still make mistakes and will make more. Hopefully, not the SAME mistakes. There are hundreds of details that go into creating any successful shop. If you need some cues or clues, check out the successful shops and designers (Nekkidtees or Amorphia for example). Don’t seek to duplicate them style-wise, but do pay attention to their methods. If you’re assuming things just happened for them, you’re wrong. They put in WORK. As tired and unmotivated as you may feel, you’ll have to put in the work as well.
4) Bounce your design ideas off of others. What you find funny or amusing, others may not. Inside jokes are great amongst you and your mates, but that doesn’t mean that John or Jane Doe will respond to or even understand it. By the same token, don’t let the fact that someone doesn’t like what you’re doing prevent you from pursuing it if you truly believe it has a chance of penetrating your chosen market. It’s probably best to critique your ideas/designs with some intensity to find the problems (you won’t find them all). While this philosophy can go either way, I think it’s best to be a little overcritical of your work than to just let anything go out.
And finally…
I’m not an expert. I’m still (always) learning and stumbling as many of you are. The team at Spreadshirt is an invaluable resource for information. I guess I would just say, before you complain, check thyself. Investigate. Anybody can put a design on a T-Shirt, but not anyone can do it well. The more critical you are of your work, the better it will become; the less rejections you’ll receive; the better chance you’ll have of moving product and satisfying those who are doing the buying.
One more thing: When you do make a mistake, don’t scream out loud. It scares the pets and your neighbors will assume you’re as crazy as they always thought you were.
I wish you all success in your work,
Mattias
Some Spreadshirt tips that may be of use... 
Re: Some Spreadshirt tips that may be of use... 
Re: Some Spreadshirt tips that may be of use... 
