One of the most important things to take note of when jaywalking is to remain calm. All too often you can see would-be jaywalkers cross a lane or two only to run back to their starting point because they see incoming traffic and panic.
Jaywalking, in fact, should be treated in the same way you would treat a martial art or a sport. Be composed, confident, and examine the situation on the road analytically.
Understanding how traffic works is crucial at this step. You should be able to predict where vehicles will be coming from, how they will travel, which lanes they will take. Always remember that traffic is dynamic, so do not look for empty stretches of road; instead, be able to notice situations where partial openings are available consecutively.
To illustrate this, take a situation where you are crossing a road with four lanes. On the first lane there is a car travelling at a decent speed, while on the third and forth lanes there are motorcycles moving much faster than the car. Time yourself such that you will be able to cross the first two lanes before the car reaches you, and by then be able to cross the last two lanes as the motorcycles have whizzed past.
Once you begin that exhilarating first step onto the tar, enter the Mode. Be aware of everything occuring around you, do not be surprised by anything, and adjust yourself to the situation in an appropriate manner.
Car suddenly speed up? No matter, either quicken your footsteps or slow down. Remember: NEVER PANIC.
Practice jaywalking across easy streets first, and only take on larger roads when you feel more sure of yourself. Soon, you too will be able to cross a 6-lane expressway in heavy traffic without getting killed in the process!
Safety notice: If a proper crossing is easily available, I'd advise you to use it instead. Jaywalking is fun and useful, but it can be dangerous, so always take personal safety as your utmost consideration. Also, the disclaimer in the previous write-up applies: The above pointers should be exercised with caution and used rationally according to your situation. I will not be held responsible for your death or injury if you are plowed over by a bike courier.