sonic trick...u probably kno bout this already...but

[Machiavelli.CF]

use sonics upB above your enemy, if they get hit with the falling spring,
it will push em' foreward just enuf so they r perfectly positioned for a d-air...
it's stupid...I KNOW! but it will get you a few % points...

 

[Tenki]

use sonics upB above your enemy, if they get hit with the falling spring,
it will push em' foreward just enuf so they r perfectly positioned for a d-air...
it's stupid...I KNOW! but it will get you a few % points...

you know what's also cool?

Spring > lagless D-air > tilt

or the elusive:

Spring > lagless D-air > jab lock :[

 

[R4ZE]

usually... if i use homing attack and miss... i hit up-b... for the simple reason that it negates SOME delay (because sonic receives more delay if he hits the ground after a missed HA)

and your right, when i hit a noob wiht a spring usually i am able to hit him with a dair... because as long as you change your direction when you use up-b so that your facing your opponent, he will often times be trying to punish the HA delay.... but instead...

he attacks into a spring, and either tings or takes damage, and then a nice dair comes down on him before he can do anything.... also... if it is lagless dair, then you can always do somthing or sheild right out of it. such as tenki was saying.. the tilts or jabs... usually i like to fsmash... but thats just me... lol

also sumtimes its good to follow a dair with a quick jump/short hop i into an aerial... and then you could try for a chase kill.