If it's Fox:
There's really not that much you can do about Fox shorthopping lasers since reflecting them is a waste of time and he'll gain on you. Just make good use of platforms if you're on Battlefield or any other stage with platforms, or carefully close in on Fox since he'll want you to come to him anyway if he's shooting lasers. Fox is going to use lasers to tack on damage before closing in, so always watch out for Fox's actions after lasers.
If it's Falco, you can use the cape but exercise caution with it. Sometimes it'll force Falco to shoot lasers at a different height, but overall you want to still avoid use of the cape since it forces Doc to commit, and Falco can move into your face quickly. You may want to mix it up with your approaches towards Falco since he can act after landing SHFF Lasers.