What works amazingly against falco is to do a jab after getting hit by a laser.
I learned from a really good player that people overestimate the hitstun of falco's lasers, in fact, after getting hit by a laser, you can usually do a dash right out of it, which will catch your enemy off guard. I take no from this blue part
Because the jab's range is reasonable and there is barely any lag, if they try to approach, the jab will catch them off guard. If they don't approach, you can then do whatever you want; some good options from there would be doing a quick dash attack, try to get a quick grab, or WD into f-smash (this one is punishable though).
Another really good use for the jab is to WD back then immediately WD forward and jab. I've noticed that with Marth, he carries lots of his initial speed when he uses a move from a WD, so when you do this, it'll almost look like Marth is sliding forward almost like Luigi when he is using the jab. This technique is very safe and can cover a huge amount of distance.