Two of mine have done ED now. Though they attended different high schools, they both followed much the same general schedule, getting two subject tests done by the end of sophomore year, and taking the SAT I at the earliest sitting in the winter of junior year (I honestly don't remember now - January? I know we had snow and worried about closings, in both cases - but it's the earliest one). They felt that allowed more time for a junior year retake, if it had been necessary, that wouldn't get in the way of another subject test in June plus AP tests in May. Both were completely done with testing (except for senior APs) by the end of junior year.
The second one got all of the "big/little/city/country" informational visits taken care of by tagging along on the first one's college visits. If I can remember back that far, I think we didn't worry too much about preliminary visits with the first one, because she played a lot of sports tournaments at various campuses and had a rough idea of what would work for her (size and location wise) already. Her schedule was also complicated by her sports schedules. Somehow or other we had all of her first visits done before the end of September of her senior year. She did some follow-up overnights in October, and that was that. S1's schedule was less of an issue; he, too, was done with overnights by October.
So far, so good (very much so for D and S1, and not bad for my inner J).
Mine are both
Js, too. As 3togo points out below, that definitely matters.