The best things I know/ see my friend do is this.
1.) Downthrow fox, and regrab him in place. Carefull he can grab you instead very early in this process.
2.) When I'm Zelda, Also I seen my peach friend fall for this trap.
My friend Taco will Lazer->Grab, Down+Throw, and tech chase with another lazer to grab. I'm not sure if he has to guess where I'm going to catch me in time, but IF I roll behind him he'll grab me again. So sometimes I won't tech assuming he'll jump after me, Which he promply just downtilts me really fast after throw or shines.
3.) If you upthrow fox fast enough to keep him from DI'ing you can get a Sex kick in.
4.) of course if you get a grab on the edge, just throw them off.
That's the stuff I seen falco's do with grabs. There may be more, or what I said may not even really be THAT effective, but it's something to think about.