I count to ten between placing attempts. An attempt involves opening the menu, selecting the type of house and having the target cursor up, then either hitting my last target macro or targetting the ground. Once I've tried to target then I count off 10 real seconds. I've also used online timers in browser windows for more accuracy.
With this method I will *sometimes* get burned. I will up it to 11 seconds if it's been a while and I really can't afford to get a hot tool because it feels like it's going to be soon.
I suspect it is something like more than 6 attempts in 1 minute will give you a hot tool, but I've never rigorously tested to see.
BTW try to place on more than one account. If you get a hot tool then park that character somewhere hidden where they will not instantly log out, I would not recommend somewhere where you could get paged on (IE the place where the house was). Just recall them to your house and log them out right outside the house, hidden.
Now log in another character from another account and try with them. It should take a few minutes for the first character to be able to place again, so you can rotate them back in if you get hit with the hot tool again.
BTW counting drives me nuts. I'm OCD so I do it enough already with all manner of things. I really can't help chanting the time, even silently in my head. After a while of doing this I want to run around in circles screaming. So it's pretty rare when I actually try to place a house. Sanity > UO.
