There is only one rule in Time Trial: finish the track in the shortest amount of time possible. But just saying that isn’t very helpful, so here are three « golden rules » to follow in order to help you lower your time:
Golden Rule n°1: Minimise the distance travelled
This is referred to in the community as « cutting » or « cornering ». It is a major time saver at all levels, including the highest level, where an improvement of even 0″10 seconds is a big deal. Try to always be as close as possible to the inner walls of the track, make your powerslides as straight as possible (for example by doing one powerslide to the left and one to the right, instead of two to the left or two to the right). On some track such as Turbo Track lap, speed and reserves aren’t a decisive factor, so it almost all comes down to how well you can follow the perfect trajectory.
Golden Rule n°2: Maximise your speed
Since Time is Distance divided by Speed, if the first rule was about minimising distance, the second rule is of course to maximise your speed. To do this, it is best to look at the pointer on the speedometer, as it gives a reliable information on your current speed. Beginner players will be mostly concerned with keeping their turbo reserves high enough to maintain Yellow Fire or Sacred Fire through the whole track without losing it. Advanced players will be happy with keeping USF all the way until the next Turbopad ramp. However, the key here are the SGs. At the higher level, the major difference between times comes down to how many SGs you got, and how long you froggied after them. Of course in order to froggy longer without losing your Fire, you need turbo reserves, which brings us to the next rule:
Golden Rule n°3: Maximise the amount of Turbo reserves you produce per second
This rule is not just about getting as many turbo reserves as possible. Instead, it is about getting them fast. Because every second you waste making powerslides or MAPs is a second wasted not froggying after a SG. Which brings us to the key aspect of this rule: always make full powerslides! A series of three short powerslides may take as much time to do as two full ones, but the two full ones will give significantly more reserves, and therefore are preferable. The only times short powerslides can be acceptable is if you need a short powerslide to cut a corner better (to respect Golden Rule n°1), or if you need to stop your powerslide anyway to start another technique, for example projectiling or doing a MAP on a ramp. However, in the vast majority of times, « the fuller the better » is an adage that holds true.
MAPs are the best way to maximise the turbo production per second, as it combines the turbo from powersliding with the hang-time turbo from the jump. Besides, MAPs can sometimes be done at the end of a froggy, thus keeping the SG speed (Golden Rule n°2!) while at the same time working on increasing your reserves. Perhaps the best example of this is at the « Peruvian jump » in Roo’s Tubes (see the Advanced Techniques guide for more details).
Of course, it can be impossible to fully respect each rule. For example, the path that maximises speed may not be the shortest path. In that case, you must try to find the compromise that will give you the lowest time. Even once you reach Expert level, you will still try to find the perfect balance between those 3 rules, for example trying to cut corners as well as possible while still having the best SG, or froggying as long as possible without losing sacred fire, thus needing as many turbo reserves as possible.