1. Do not hang original artwork in your bathroom. In fact, do not hang anything in there that you do not mind throwing in the trash. Here's the problem: humidity. Heat and steam from your showers makes the bathroom high in humidity. Framing is not air tight, even if there is paper covering the back. Moisture WILL get in there and ruin your artwork. If you really want to hang something in your bathroom, make a copy of it and hang that in there, hang the original somewhere else. This goes for pieces wrapped around a canvas stretcher too. Those stretchers are made out of wood, and they are not sealed with anything.
2. Use UV protective glass, always. I don't know how many times a week I hear people come into the frame shop with their old glass wanting to reuse it. I explain that glass from a few years ago does not have the UV filter on it and will fade, badly and quickly. Their response is always "Well we are going to hang it somewhere where it does not get much light". If you can see the piece in the daytime with the lights off, it is getting sunlight, and being damaged. UV protective glass is not expensive, a 8x10 piece costs around $3. Those frames that you buy from Walmart, Target, Hobby Lobby, Michael's, and so on, do not come with UV protective glass. Unless it says that the glass has a UV filter, it doesn't. Think of it like sunscreen. You wouldn't go out into the sun without it, don't frame your artwork without it. Anywhere that does framing can cut you a piece of UV filtering glass on the spot.
3. Do not use saw tooth hangers, ever. They will give way, your piece will fall, your glass will break, your matting and/or artwork will be ruined. I do not know how many pieces people bring into the shop in a week because the glass broke because it just fell off the wall. Hang your piece with wire or D-Rings.
4. Yes, you do need a mat, or glass space. The point of the mat is to keep your artwork from touching the glass. If you do not do this your artwork will become stuck to the glass, forever.
5. Do not frame to match your decor. If you frame a piece right, so it matches the artwork, not your couch, you will never have to frame it again. Your wall colors change, furniture gets replaced but if you frame your piece right, it will outlast you.
6. Yes, you need glass. Works on canvas aside, you need glass. Besides all the protection from #2 up there, your piece will get dirty, dusty, and damaged. If you have an canvas piece, ask the artist if the piece has been varnished. This layer of varnish will protect the piece from UV damage and will give extra protection when dusting.
7. Make sure your frame is wood or metal. Most of, if not all of the frames that are sold in the big box stores are made out of some sort of plastic resin. They are cheep, light weight and if they chip or break you are out of luck. Wood and metal frames can be re-sized and repaired, those resin frames cannot. I am not use how these resin frames are made, or what they are made of exactly, but I am guessing they are not of good quality, most are manufactured in China, who knows what is in there.
8. Use all acid free materials. Do not use cardboard for backing or tape your photograph or artwork in with masking or office tape. Have you seen masking tape that is just a few years old? It is gross. I do not know how but it gets 10x sticky-er and those chemicals that make the tape sticky are not coming off. Use acid free tape or even better those Mylar corners. You can get those in the scrap booking department. For backing use acid free foam core or core plastic. Those mats that they sell at Hobby Lobby and Michael's are not acid free either. I had to re-cut mats for EVERYTHING.
9. Don't fix it yourself. Unless you are an expert, do not fix it yourself. Accidentally poked a hole in your canvas? Take it to the artist or someone for proper repair. The artist is not going to yell at you, they will be thankful that you are wanting to take care of their piece. Some may even fix it for free. Do not just stick it back on there with a band aid.
10. Hang your artwork where it will not receive direct sunlight. Even after all that UV Protective glass, it only filters 99.9% of UV damage. Do not hang artwork in your sun room, or in that path of sunlight that moves across the room during the day.
Bottom line, don't be cheep and do your framing right. Making a bad choice because you are trying to save $5 now is just going to cause you more hassle, and money, later on or it could ruin your piece entirely.