There really are no techniques. Anything goes because anything has the chance to work. This being said, there is no need to “formally” learn techniques. Techniques are tricky because they can easily be stolen. All it requires is a visual cue and understanding what is occurring. From there, a person can reverse-engineer what is being affected and come to its origin.
One can also make up one’s techniques according to one’s faults and shortcomings. For example, I noticed that my backhand was not as powerful as my pak or tan or bong or fook. So I made up a drill involving it, a punch and gaan sau. I practice it so I can improve my hand speed.
A partner isn’t really necessary. It is helpful to receive feedback and reaction from a living being. It is helpful. But when it isn’t possible – like for me – then I just work on myself. Because if I get better at going it, with “flow,” then I can reproduce the same results against another person.