cross t's

cross (one's) t's

To do something carefully and make sure that every last minor detail is completed. Please make sure to cross your t's when signing this contract. I made sure to cross my t's when installing the circuit breaker—you can never be too careful with electrical work.
See also: cross

cross (one's) t's

To be thorough or painstaking in attending to details.
See also: cross
References in periodicals archive ?
to the business and just wanting to emulate my idols, I would try probably harder to cross T's and dot I's and hit certain notes," she said.
Everybody wants to dot i's and cross t's and you notice the wine is still sitting there but they've just asked me to be a little careful while they're under great scrutiny and I'm happy to do that.
Similarly, experts and contemporaries chime in at various points to heavy-handedly dot i's and cross t's.