There are a lot of different marijuana training techniques to help growers boost their cannabis plant's harvests and subsequent yields. Some training techniques are a little bit more difficult to employ than others, it is important that you do not accidentally harm your cannabis plant too seriously when trying out training techniques.
For example, low-stress training (LST) is one of the most common methods of cannabis plant training which involves physically spreading your plant's stems and branches horizontally to expose a larger surface area to the light. 
High-stress training (HST) is a similar technique to LST, however, this one is a bit more difficult as it requires that you physically harm your plant by bending and, in some cases, snapping the branches so that they lay as close to flat on the ground. HST serves a similar purpose to LST but it is a bit more extreme. HST requires a certain amount of effort to get right, however, growers will see a substantial increase in their yields as a result.
There are a whole bunch of other marijuana training techniques, Kronic outlines a number of them here in great detail, however, if you are yearning for more information then head over to Homegrown Cannabis Co.'s blog for further educational cultivation content.