For the first way to work you have to have really short finger nails. I am learning to play the guitar so my nails are very short. I sit on a chair or lie on my back on the floor. I coat the middle and index fingers of my right hand with saliva and then push them into my 'gina. then I curl the fingers upwards so it feels like the tips are facing upwards and pushing against the front wall, then I slowly pull my fingers out. The sensations from the pressure from my finger tips are unreal. So it's basically a case of straight fingers in, curled fingers out. Awesome!
Sometimes I use a water pistol that I got from my little brother. It looks kind of space aged. Anyway, I fill it up with quite hot water. I build a small pile of books with a towel over it and then put the water pistol on top of that, holding it so the barrel bit faces upward. then I put a knee on either side of the books and sit down on the water pistol. I love the feeling of the smooth warm plastic inside me and when the sensations get really intense I use my thumb to squeeze the trigger as about 4 or 5 times as quickly as I can, spraying the hot water inside me, which is why I need the towel. I am always careful to clean up carefully afterwards, and have never had any problems doing it this way.