I never studied the spirit board, all I say is from personal experience, so it might not be completely reliable.
I started in a group of trusted friends, and it worked. The space we "played" (I don't have a better word) was filled with energies, as it was an old house that was filled with love and all kinds of objects from my childhood and of the previous owners. The spirits in this instance were very different, some "evil" or distraught, others kind, others not wanting to speak.
We encountered many spirits ( :D edr7677) that would talk in gibberish or just random sets of numbers and letters that would not make sense, and our eyes were open. A lot of spirits contradicted what they said a moment ago, or what another spirit said, many seemed unsure about things, some spirits felt like they were just making up stuff as we asked.
When we tried to play alone the planchet moved, but slowly and the spirits connection was weak (I barely feel its presence, while the other spirits I connected to with two or more people had a strong presence and could move the planchette easy and fast.) I prefer groups because of this.
Then we played in a modern house in an empty room; this house was empty, cold and filled with rich objects. The energies were much the same (cold, unwanting, ect.. ), and so this session had one spirit, no matter how many times we un summoned and re summoned, the same spirit came back. From this, we concluded that because this house was just made (about 20 years ago?) and the room was empty, and usually never used, the lack of history and "presence" played a role in the lack of spirits. (the spirit of this house also seemed to be disinterested in everything in general.)
I have never seen this on a site, so I'll share it with you. I don't know if it is dangerous, but I have never had trouble with this. If you put one hand on the planchet and summon a spirit, and then place your other hand on a paper with a pen, you can let the spirit draw or write with it. In my case, the spirits just scribbled things (probably because the lack of effect on the physical world for so long got them excited?). I visualize my spirit moving out of my hand and then moving the spirits grasp from one hand to the other. I'm interested to see if it works for you, but please be safe if you do try it. I don't know what could happen if you mess up, and although I don't find spirits to be as dangerous as Hollywood makes them, I do understand that they should be respected.
Have you tried saying "are there any spirits with us tonight?" as a statement to start? (If the spirit says no, say "wish you a happy night, goodbye" or something positive, but make sure to let it leave.)