When you say dealing with them do you mean avoiding or stoping them..
Pretty much what Dipn said. If you don't have enough time or the proper positioning to space an attack that will beat his approach (this happens a good bit vs falcon since he is so fast), you're most likely going to want to shield the incoming aerial and buffer a roll away from falcon (this is what I meant when I mentioned ganon's rolls inmy last post; while shielding the incoming attack, simply hold left or right on the c-stick to roll on the first possible frame).
If you have enough time/the proper positioning, you can beat falcon's nair with a spaced bair, uair, or up-angled ftilt. Fair can also win the exchange when fully spaced, and jab can also beat out the nair if it isn't spaced properly (when he's coming in hard).
CC jab (or even jab + downward ASDI) can technically beat the nair every time if he's within range. The first hit of falcons nair has no knockback growth (does the same thing regardless of the enemy's damage), and jab is just fast enough to hit falcon before the second hit of the nair comes after you've absorbed the first hit. Not a very reliable strat unless you're very fast and become consistent, but it's good to know.
For the knee, you have similar options, but you have to know what you're dealing with. Trading hits with the knee is seldom favorable for ganon. When challenging the knee, you must be ready to DI properly in the event that you trade hits (and obv if you are at kill% you want to chose your battles wisely). Imo up-angled ftilt, uair, bair, and fair are good for this.
