ask for trial.
you'll get your summons in the mail. write to the prosecutor's office at courthouse your case is up at and send them a disclosure request. you can find the forms online. when you send the form (usually by fax, or in person - they're too outdated to have email), ask for the manual for the device the cop used, the training records of the officer on the device, all memo notes the officer took, all video/audio recordings from their investigation, and calibration/test records of the device from the officer's shift.
if they have it ready for you before the trial date, go pick it up. read it over for any possible defences: was the officer using the device properly according to the manual? was he/she stationary or moving while using it? were there other cars in between you and the device that could have affected the reading? was the device tested properly? (usually three times before and after a shift) etc
GO TO YOUR TRIAL DATE. when you have a chance to speak to the prosecutor (could be forever, you literally never have to show up at 9 AM unless you are represented), ignore his/her questions to you about what you want to do and ask him or her if the officer is here because you want to review his/her notes. they will say yes or no. if they say no, say you want a trial because the charges will be dropped.
if the officer is there, and you want to run a trial based on a possible defence, tell the prosecutor this. you may get a way higher penalty if convicted depending on the charge.
if the officer is there and you don't have all your disclosure yet and you want to run the trial or you want to adjourn it to another day and come back to see if the officer shows up on the second day, tell the JP you wrote and asked for disclosure and they haven't provided all of it yet. you will get a new date to come back.
if the officer is there and you want to take a plea to a lesser fine, the prosecutor will offer you their position on a plea. you can try to negotiate it a bit if there's a lesser included offence you can plea to. you can sometimes ask the JP for an even lower fine depending on if there's a min fine and if you have "exponential financial circumstances" that make it impossible for you to pay that amount.
don't ever just pay the ticket if you have the time and are willing to go to court to fight it because you almost always will get the option to pay a lower fine/plead to a lower offence or pay nothing because the officer won't show or because the prosecutor doesn't have enough evidence to prove the offence.
don't bother doing early resolution because whatever they offer at early resolution, they'll offer on the day of. and you won't have the option to see if the officer shows.
if you want to look up past defences to speeding that have succeeded, go on
https://www.canlii.org/en/ and do a search for your offence and the jurisdiction and read some case law.
also everyone should download waze and use it while driving because it warns you of upcoming speed traps, red light cameras, general police sightings, etc.