I think BizResearcher made some great points and his/her advice can get you headed down the right path.
I don't own a gift shop, but many of the things that I went through in opening my own retail shop will probably translate over to ours.
If you have your heart set on a physical retail location, the location is essential for starting out. That was one of the best things I did in opening my store. I opened in a strip plaza, right next to a new restaurant so people wanted to try this new restaurant out and low and behold, there is my new little store right beside it. I would have people come in, look around and ask me what I do then they would go over to the restaurant and eat. After you get established and have a loyal clientle, then location probably doesn't matter as much.
Don't go into this business expecting to cover you living expenses for awhile. Some people say that you won't make any money until 2 to 5 years, which I think is wrong, but the money you put into the business and the money it makes needs to stay in the business, it is the only way to grow the business. Many, many, many businesses fail because lack of cashflow either within the business or your personal finances.
My business has been profitable since the first month I opened, but I've only take maybe $2000 out of it in almost 2 years.
Another thing that I would suggest is talk to other retail store owners, ones in your trade would help, but you'll probably find many are relectant to talk to you because they will think of you as competition, which you probably will be. A better approach might be to find some businesses that will be similar to yours but not direct competitors, and you might be able to place some of your product or flyers in their stores and cross promote each other.
And lastly, have you considered starting this venture as an online business first, maybe test the waters and see if people are buying this stuff. Yes you will have to spend some marketing dollars, but it would be better to spend some and see if it might work or not, than spend everything and hope and pray.
One more thing I thought of, talk to your friends, family, facebook friends, strangers in line at Walmart(there's always weird people that want to talk in Walmart checkout line) and everyone you run into. Pitch your idea, ask them if the things you are thinking of offers are things that they would buy, don't ask them if the business is a good idea or not, most people will be negative and say this is the worst time to start a business.
If you want to talk more, send me a PM. WOW, that was long.