Foley Question

Hi everyone- I’m a new grad and I’m wondering how far a foley should be advanced before inflating the balloon. I was taught in school advance a little further after urine starts to flow. In my practice I’ve had to insert a few foleys and every time it feels like my preceptors want me to advance it super far and then when we secure it there’s hardly any slack on the foley. I’m almost done with my orientation and I’m just wondering how to have the confidence that the foley is in fact in the bladder before inflating the balloon.