IMO a subtle but important technique to teach or to learn is how to take away or manipulate your opponents angles to punch from. In simple terms, take drawing a shot by feinting an opening, then making your opponent miss and lose balance. For me it's the most important and understated part of Mayweather's defence. He puts himself in positions were you have to reach and charge for him, and he knows exactly where you will be so he can counter. Here is a gif I stole from a different thread.
Also worth noting in this example, he knows Ortiz wants to keep his foot outside, so he concedes the outside in order to gain the upperhand. As a southpaw myself I often take advantage of the fact that a lot of orthodox fighters go into the ring fixated on the idea of stepping to the outside, but they can be unsure of what to do when you let them take it and roll back under the inside to open up angles.
Always better to be the puppeteer than the puppet IMO!