When do you start your OPKs?

Sarah • Mom to Wyatt 💙 and Noelle 💗
Hey y'all! 
This is mostly just out of curiosity on my part. What day in your cycle do you usually start taking your OPKs?  I usually start once my CM loosens up and it's not sticky anymore and becomes more creamy. (Sorry, TMI)
Do you have a time you usually start them, and what time of day do you take them?