Trick looping is this: finding a way to grind around, full circle, for a theoretically endless amount of time.
Basically you're just grinding the same rail back and forth without touching the ground to get a ton of points. The videos in each section should show pretty well what trick looping is.

One of the easiest and well-known trick loops.

Tips:
--Keep your speed up, or you won't be able to make some of the longer jumps.
--You MUST wallride the sign after the sprayable car and Rokkaku truck. If you don't, you won't have the speed or elevation to make it across the street.
--This was my first trick loop. Just keep practicing, you'll get the hang of it in no time!

The sewer in this area allows for lots of experimentation with trick looping. If you want to get better at trick looping, practice here.

Tips:
--Falling into the water will reset you at a good position, right at the bottom of the stairs. Therefore, failure is not very harshly punished here, so don't be afraid to mess up. Kogane sewer is a good practice area.
--Jump up the stairs railing to keep some of your momentum and to be able to get all the way up them.

Probably one of the harder ones. It's a fairly large loop that covers a lot of distance.

Tips:
--Speed is everything here. There are a lot of jumps that may seem impossible to make at first, just remember to jump jump jump whenever you have the chance, and you'll be able to just barely make it.
--Don't worry about hitting your head on the skywalk near the spot where you start. Your momentum will not be lost, as you'll see in the video.
--Feel free to improvise, there are a lot of grindable rails here. Don't forget the medians on the streets.

Relatively simple, but it has it's tricky parts.

Tips:
--Hold left on the analog stick BEFORE you jump to make a tighter mid-air left-turn.
--Jump a lot while grinding up the incline's rail so you'll have the speed to make it to the next rail (and so you don't fall off)
--Wall-riding isn't 100% necessary here, but it gets you a few extra points, and it helps you cover that long distance.

Probably the hardest one, just because of how unforgiving Grind Square can be.

Tips:
--After jumping from the Golden Rhino Statue in the middle of the stage, you'll land on a slope going up. Wait until the very end of this upward slope to jump to the pipe (where you will then start going up the building). If you jump too early, you'll hit an obstacle, and fall down. So wait until the very end of that upward slope to jump. This applies for both sides.
--Jump, jump, jump while going up, up, up the pipes. Otherwise you'll start falling backwards, and no one wants that... just don't jump too much, use your best judgement to make sure you don't jump past the end of the rail and fall down.
--While practicing, you'll likely fall down quite a bit. That's probably what makes this one so frustrating, so just be patient and keep practicing- you'll get it.

In a few of these videos, I spray-painted the graffiti locations that I passed. You don't necessarily have to, but you might as well spray them. They give you 500 points each, and since you're going for a score in general, you might as well take the free points.

Thanks for using my guide! I hope you're enjoying the game, Jet Set Radio is my favorite :D

I tried to keep these trick loops as simple as possible, but it may not necessarily be that way all the time, especially in Grind Square (trick looping in Grind Square is pretty difficult no matter where you try to grind). Nonetheless, just keep practicing and you'll get the hang of it!

Feel free to improvise as well. There are tons of different ways to do trick loops, these few videos barely scratch the surface on all the possibilities available in each level. Post a video, I'd love to see what kinds of loops you've come up with!

Thanks for reading!