How does the 3D dash and wedge notation work?

To make life easier we often treat molecules as flat - for example we draw methane on a page as a carbon with 4 hydrogens bonded to it at perfect 90 degree angles. This isn't really the case. Electron-electron repulsion between covalent bonds (electrons are negatively charged, so repel each other) increases the energy of a system, so a molecule will want to minimise this interaction by placing these bonds as far apart from each other as possible - this leads to a bond angle of 109.5 degrees between each bond. Visualising this involves thinking of a tripod with three feet, with one extra length going directly up. How do we draw this? Firstly we recognise that two of the bonds will be in the plane of the paper (e.g. the vertical length and one of the 'feet'), meaning they are flat on the paper. This means that out of the other two, one will face towards us, as if it was coming out of the paper, and the other will face away from us as if it had sunk into the paper. We represent the bond facing us with a wedge, and the bond facing away from us with a dashed line.