How to take accurate OPKs

Sorry if this is a stupid question, but for the tests that DONT use FMU, like OPKs, how do you take them consistently? Do you pick a certain time of day and just not drink any water or pee for like 2 hours? Maybe I’m weird but I chug water throughout the day and pee about every hour so planning that anytime other than FMU is really hard for me. Would love to hear from others what you do and any advice for me, thanks!