I'll quote ArcNatural on this one:
If you want to get better at something, when you play focus only on that one thing. If it's tech chasing, spend the whole match focusing on tech chasing and try to set up opportunities to tech chase. Keep doing this until you see serious improvement.
Just do that. Arc knows what he's talking about and is one of the most interesting tech chasers I've played. He's the type of guy that can tell you ahead of time which way you're going to tech, it's kinda creepy. Elen, on the other hand, just watches people tech and follows it. He gave some advice on what to do so I'm not so predictable when teching, and I'll share it because it'll probably help you too.
You almost never want to roll tech. It's so easy to follow. The only time you want to roll tech is when someone expects you to tech in place. Instead, you should be focusing on what to do AFTER you tech. With Marth I'd recommend up-tilting right out of a tech. With Falco, if you time a shine right, it's nearly impossible for them to hit you right out of the tech. Focus on this as opposed to just where you're teching.
Maybe that helped you, too, since you'll see the better players doing that. And a suggestion: If someone misses a tech, dash dance back and forth in front of them. A lot of people will just do a getup attack. Just dash away and dash back as they finish and grab them. And Elen's completely right, rolls are so easy to follow--especially with Falcon.
Hope this helps.