well the board wouldn't work for a number of reasons, commonly you're not focusing. when people have sleepovers and sit around and it starts moving like crazy and you get all these spooky tales, someone's moving it themselves. [normally willingly but sometimes it's subconsciously] in reality, it's very rare to have a board react most people claim it does. if you're using it as an actual magick tool, and not for a toy, you need to focus when you use it, as well as charge it with energy. like with an athame, wand, cauldron, besom, or whatever, you need to charge and bless it, otherwise, you could use a butter-knife and get the same results. Cast a circle to protect yourself
personally, i work the ouija board with three people, two people work the planchette ad the third asks the questions and records the results. sometimes the people channeling with the planchette are blindfolded, but we concentrate better with our eyes shut anyway so we don't do it as often. the blindfold ensures whoever's using the board isn't messing with us. you can do it with just yourself, but your eyes need to be open [for obvious reasons] first, meditate, clear your mind and become relaxed. when ready, place your fingertips just above the planchette and ask if there's a spirit who wishes to speak. it should eventually go to yes. keep in mind some important things though
Be polite, if you offend a spirit you can be attacked. also, remember to thank them before they leave, and point out it was a visit, say something like 'thanks for visiting my home, have a safe journey back'.
Don't pry, certain subjects [commonly how they died] they do not wish to speak about, so if they say they don't want to talk about it, don't demand or keep asking.
Do not damage the board. this can cause a lot of negative things.
Cleanse the board, the room and yourself after using the board just as a precaution. if you spoke with a spirit who seemed dangerous, cast a protection spell as well.
onto your questions though, using a board in a strictly christian home shouldn't effect it. spirits wander the earth, there's no place that's really off limits. graveyards are surprisingly empty, because it hold no real sentimental attachment, the only spirits in their are waiting for something, or refuse to leave their body [basically refuse to admit they've died] many wander looking for a place to call home, but there are those who attach themselves to loved ones, treasured items, their home, or people that remind them of a loved one. if you cannot speak with a spirit in one area, try in others [if you can] around your home. if you still cannot, your home might be a 'dead zone' [as my friend would say] for whatever reason, no spirits dwell nearby, or were passing through.
they can be made out of anything really, but wood would be best, it's harder to damage than say paper, look nicer, and will carry some magical properties depending on the wood you chose. Cedar might be the best, it is easy to find, and carries spiritual properties useful with communicating with spirits. the planchette could be made from the same wood, or a different type, could also be a crystal, a coin, a cup/glass, and basically anything you can use to point.